Nick Carr has an eye for the obvious today:

In another sign of what the future holds for Web 2.0 in business, the Forrester survey found a clear preference among CIOs for buying a full suite of Web 2.0 tools from a large, established vendor. 74% of CIOs said they'd be more interested in investing in Web 2.0 if all the tools were offered as a suite, and 71% said they'd prefer the tools to be "offered by a major incumbent vendor like Microsoft or IBM [rather than] smaller specialist firms like Socialtext, NewsGator, MindTouch, and others." Web 2.0 startups hoping to make big inroads in the enterprise market will face some big challenges, particularly as the larger vendors release their own suites of tools or incorporate them into existing products. You can bypass the CIO on a small scale, but it's difficult to bypass the CIO when it comes time for a company to standardize on a particular product and vendor.

For established companies, I'd say "well, duh". They say that for the same reason that they keep buying WebSphere and Microsoft Office. The entry point for the smaller guys isn't with the big, established firms - it's with smaller outfits who are willing to take a chance on something that's either cheaper or offers higher productivity - or both.