Application platforms are very profitable in the software business. Platforms attract developers. Developers build all kinds of interesting applications...which attracts users. Millions of users mean your platform will generate revenues for a long, long time.
Wikis and blogs are great collaboration tools, but they are now moving beyond that to become application platforms. Socialtext and JotSpot (acquired by Google) are building out suites of office productivity applications built on top of a wiki platform. Telligent and Blogtronix are building application platforms on top of the blog model.
Web 2.0 applications are more than just "webifying" existing apps. Web 2.0 applications are inherently interactive and collaborative at every level of the application. They are simple to build, easy to manage, and cheap to maintain. Increasingly they are being built on new platforms like blogs and wikis, and using new tools like AJAX and REST.
Dan Bricklin, inventor of VisiCalc, the first spreadsheet, has created a new wiki based spreadsheet called WikiCalc. It is not just a spreadsheet with a web interface...it is a web authoring tool that combines the ease of authoring and multi-person editing of a wiki with the visual formatting and data organizing of a spreadsheet.
Jotspot, recently acquired by Google, has built several office productivity applications like spreadsheets, word processors, and project management tools on top of the wiki platform.
Telligent has a blog based application platform called Community Server. The Microsoft StartupZone site is built on top of Community Server. The site appears to be a standard HTML web site, but it is in fact a collection of blogs that drive interactive content to every section of the web site. Blogtronix is working on a similar blog based platform for enterprises. No web master or HTML skills are required to manage and maintain the site. A simple blog edit window generates all the content and graphics that appear on the site. UPDATE: Robert Scoble has a video interview with Blogtronix and a demo of their platform.
These new wiki and blog based platforms are an example of the promise of Web 2.0. They introduce a whole new way to build collaborative, interactive, web ready applications that can be hosted "in the cloud" or inside the firewall.
Platform shifts happen every 10 to 15 years. We may be witnessing the start of a new platform shift with Web 2.0 style blog and wiki platforms.