Hi,
It's exciting to see some feedback on OWA Beta1! Here are some answers.
Jesse: Yes, a Browsable Address Book is available in OWA2007. I think you'll be quite pleased when you see it. Come by the Exchange booth at TechEd in Boston in June and we'll give a demo, or wait for our Beta2 release to become available this summer.
Matt: The monthly calendar view is unfortunately covered by the "you can't make an omelette without breaking a few eggs" policy of our OWA rewrite. That is: we didn't have time to rewrite all the OWA features, so we had to plan on removing a few to start with an then add them back again later. We know the monthly calendar view is a feature loved by many users and it will come back at some point (but it is not in Beta1).
Joseph: Firefox users will get the "OWA2007 Light" experience, which is a much improved rewrite of "OWA2003 Basic". Listen in on the posts to the Exchange blog and you should see a post on "OWA Light" before long.
Mike1816: Yes, when you look at message headers through the OWA UI you'll be able to see all the messages headers expressed in the MIME of the message.
Aaron: See the answer for Joseph above. We will still have the best OWA experience only for IE6+ users in OWA 2007, but the non-IE experience has been dramatically improved. Which browsers we support with the best experience and the "Light" experience is mostly a matter of development and test costs. The support lists may change in future releases.
Brian: Q1: If you keep Ex2003 mailboxes you don't get the new OWA. The only OWA2007 feature your users get to enjoy are the updates for OWA Forms Based Authentication. Other than the authentication, users with Ex2003 mailboxes will continue getting Ex2003 OWA even with an Ex2007 Client-Access-Services server.
Brian: Q2: OWA2007 will be showing the GAL and let users navigate other Address Lists. msExchQueryBaseDN will still (as in Ex2003) be the mechanism available to show only subsets of the GAL to certain users.
/K