A useful summary -- note that Google has also already acquired at least two companies to advance its future presentation-oriented tools for Google Apps, incidentally
But Google Apps has traditionally lacked some of the industrial strength it really needs to convince organizations they should be considering Google Apps instead of locally hosted alternatives. In addition to lacking a PowerPoint-like tool and having applications that died when an Internet connection wasn’t present, Google had some weaknesses on the security and compliance front. Through the partitioned version of GMail that’s offered as a part of the Google Apps brand, e-mails could not be secured through encryption. Nor is there an easy way to encrypt Google Apps-based documents (eg: word processing, spreadsheets) at rest (in other words, while they’re sitting on Google’s servers, even if it’s in a private partitioned area).
From a compliance perspective, Google offered no direct method for archiving e-mail in a way that it could be easily “discovered” later, perhaps due to an investigation by a Federal agency. While these two issues were not of primary concern to many small businesses, they’re clearly issues that are of import to big businesses and public corporations. The same sorts of companies that couldn’t possibly consider Google Apps for e-mail without an easy migration path off of Exchange Server or Lotus Notes.