Is it just me, or are we seeing a pattern right now where <a href="http://www.google.com/">large</a> <a href="http://www.apple.com/">companies</a> introduce new platforms, with the aim of easing fragmentation issues in mobile whilst actually complicating everything and making them worse? Symbian, Java, Flash, Mobile web, or SMS/MMS were the principle ways to deliver apps. Now we have iPhone-specific developer guidelines and Android to contend with - neither of which will dominate the industry totally.
The Google announcement was interesting, though as others have noted these sort of industry initiatives aren't exactly new and they have a tendency to peter out over time. I didn't find it quite as light on detail as some did: in particular the emphatic "we will provide open platforms that let developers do anything" was a novel message from a mobile OS provider; as an industry we're accustomed to being locked down.
Who's this going to put pressure on? It looks to me like a move against network operators, who compete with Google for ad revenue, are keen to own the customer experience, and currently own the customer relationships. Sure, they currently pay for an operating system so might lose a few dollars off the bill of materials for a new handset (presuming this cost saving is passed on by handset vendors). So in this context it looks like Google and Ovi scrapping for the end-user experience, both squeezing the operator slowly out of the picture (if they succeed).
And for developers? I'm finding it difficult to feel optimistic that more platforms leads to less fragmentation...