Google Apps makes huge sense for Google as business productivity and collaboration suites are one of the most preferable way for enterprises to move into the cloud. Though Google Apps has its sets of shortcomings due to which it is not ready for big ticket enterprise adoption,its more than sufficient for small to medium businesses for which rudimentary colloboration and document management is sufficient for the most part.
Flexible Collaborative work spaces with advanced level of document lifecyle management on the lines of sharepoint online is not available in a single Google Apps component.
Google Sites, Google Drive and Google Docs in combination can achieve this to some extent. The tight integration of Google Drive with Gmail raises several question marks from enterprise IT - what happens when an employee leaves ? Does he create new Gmail account for office use? Google Drive is more of a personal storage system.
The TCO for Google Apps can shoot up if the requirement is for advanced level of management,security and compliance. For these third party support has to be purchased . The customer services too does not stack up as well with office 365 as of now.
Offering is evolving rapidly - Google is rolling out new features and discontinuing few existing ones at a rapid pace. Recently it stopped free signup for google apps and is preparing to provide paid customers enhanced levels of support.
As more and more functionlities are baked into Google Apps,need to rely on third party tools and addon solutions for regular usage scenarios such as workflows etc will go down - This will not only make for more integrated enterprise user experience, but also more cost effective as purchasing third party solutions for regular enterprise usage scenarios is already in built.
Offline support for Google Docs in Non Chrome can be the real game changer for Google Apps, should that happen! Concurrent versioning management is another feature on enterprise user wishlist. Google is already working on complaince solution in Google Vault. Encrytion support is another WIP feature.
Along with Google App Engine there are possibilities galore to build customized solutions such as Knowledge Management,Reporting, Asset Management. All in all, Google Apps is well on its way to achieve a significant presence in enterpise segment.