Just seen this preview of Google Wave:
Letting the implications sink in but if Google migrate all of their (commercial and consumer) GMail users onto this platform when it launches next year this could become the new paradigm for enterprise(to-enterprise) collaboration pretty quickly: email, IM, documents and media sharing. As Rod Drury comments: the classic Exchange email model is just broken.
Google are going to open-source the APIs - how many new apps could be built upon the top of this and what new business models could that lead to? (Google exec quote: "...this again is a very early release and at Google we have quite a luxury that in the beginning of the life of a product we focus exclusively on technology and making a product successful....the question of monetising we deal with later"). Yeah right.
(Incidentally one of the jumpouts of the demo was the multilingual collaboration on a document - 4 users editing in English Chinese, Hindi(?) and another asian character set all at the same time! - not sure if this is in Google Docs already, but mindblowing compared to just a few years ago)