The NY Times' John Markoff is covering MS' latest big announcement - they are announcing a new line of business in the IP communications arena:

There is a great deal of brave talk from existing players about being both a partner and competitor to Microsoft, but in fact they should be about as glad to see Microsoft as the minicomputer industry was to see the upstart three decades ago.

In fact, Microsoft is opening a new front in its software strategy that mimics its Windows and Office approach to desktop and corporate computing.

The latter assertion is an interesting one. They are going to have to target the enterprise space, and get IT departments to really push, because messaging software is common (skype, AIM, Yahoo) and free. If they see this as an "Office Size" business, it's going to require more than a software release - they have to convince people like me to stop using skype and start using their stuff.