As cloud computing goes, so do two complementary technologies - application services, and web services. It's easier to split these into two distinct sections, though it should be kept in mind that they are simply different manifestations of an overall move towards distributed architectures that has been ongoing for the last several years.
Applications services consist both of traditional desktop applications that are increasingly being "replicated" on the web, and larger scale, typically data-centric applications that are usually targeted towards a specific vertical market like customer relationship management (CRM) applications such as Salesforce.com. This category of services also contains what I see as an increasingly dominant theme for 2009 - community management systems.
Webmail has long been the "success story" for application services to the extent that standalone mail clients such as Outlook are being increasingly replaced with web-mail based counterparts (including Microsoft's entries into that area). This is a profound shift from a services standpoint, because as mail moves primarily into this space, it can be aggregated with other messaging services - syndication feeds, chat services (increasingly across XMPP), XML messaging via SOAP and so forth.
Yet web-mail is also important because such mail applications usually tend to occupy a significant place in the work-flow for most people, and the more this moves out of the realm of dedicated desktop devices, the more that it diminishes people's use of other non-desktop systems in favor of browser oriented ones.
While web-mail went mainstream in 2005-06, other pieces of the traditional "work desktop" - word processors, spreadsheets, personal information managers, presentation creators and vector drawing tools - seemed to reach a similar tipping point in 2008. Google formerly released its Google Apps suite, consisting of a word processor, notebook system, spreadsheet editor, and presentation tool, perversely set using the Open Office ODF formats as their defaults. Zoho released a similar (and more highly powered) set of tools to accomplish these same tasks, again (as with Google) for free for individual users and at a low subscription rate for dedicated corporate accounts.
The uptake for these web-based desktop applications has been, until recently fairly slow. Part of this had to do with the ability of these applications to work offline, a capability that's critical to the success of application services. Most suites now recognize this, and are utilizing different tactics - from persisting critical pages within browser embedded databases to writing modular extensions for browsers to give enough support for these tools to let them work well in an offline setting. As this capability has improved, so to has the uptake of interest in these tools.
My expectation for this class of applications is that they will continue to see steady growth and adoption through 2009, though not really explode in usage until 2010. One reason for this is that the cost argument, so critical to general cloud computing in 2009, is not as applicable here. While high priced office suites will certainly be hurt by the slowdown (expect significant drops in the price of Microsoft Office as the recession worsens), there are enough freely and inexpensively priced desktop based office systems already in deployment that the cost argument does not become as big of a factor, and the other arguments - ease of access across multiple systems and the ability to work collaboratively - I see being much less significant through this year.
By mid-to-late 2010, however, I see broadband access actually improving significantly, as WiMax and related networks get the bugs worked out of their systems, as the cellular networks and cable networks begin to merge significantly and as more money gets pumped into boosting broadcast Internet coming from the Fed and the states in order to try to jump start an anemic employment scene. This will have a major influence on the application services space, including the desktop analogs.
The second class of applications that I see making a huge jump in the next year are going to be those dedicated to specific industry verticals. My gut feeling on this is that there's been a major shift going on in distributed systems as various XML industry standards have finally stabilized. These applications are going to be one driven by XML databases or XML/SQL hybrid databases, utilizing declarative constraint languages in order to build and edit XML documents in specific language domains. While a lot of the foundational work is in place now, I really see a lot of these begin to emerge in concert with government infrastructure efforts, as these applications actually work best in environments where a number of different actors have to interoperate.
I'll have more to say on these when I talk about web services and SOA in the next section.
The third big class of applications I see, as mentioned before, is in the community software space. We're reaching a stage where the blogging and community tools that were first spawned in the early part of this decade have reached a deep level of maturity, have garnered rich development communities, and now have hundreds or even thousands of community-developed extensions to act as building blocks. Applications such as Drupal, Movable Type, Joomla and others, as well as corresponding commercial tool-sets such as Microsoft Sharepoint, which I see continuing to evolve and mature over the next year, possibly merging with the broader Azure initiatives.
On the other hand, what I don't see much of is non-IT in-house software development. Beyond the financial pressures there (though that will be a huge factor this year, of course) I also think that we're reaching a stage where application development increasingly involves threading data streams through filters, processors and viewers. This is a big part of what AJAX programming is all about, after all. The era of huge, enterprise-wide monolithic applications is nearly over, and with it the primacy of the IT department and the need to create the massive projects that consumed so much time and money in the last decade.