Exchange 2010 install & 2003 Transition

Hi All,

Ok im about to install Ex2010 into a 2003 Exchange environment and run side by side while I transition, I have......

Prepared AD
Installed all the hotfixes
installed a new certificate on the 2003 server with SAN details

Read many reviews but still have a few questions...

When I actually install 2010 will I still have to envoke the free/busy switch on Outlook 2003 clients that are still connected to Ex2003?

Once 2010 is setup will Ex2003 still work as normal until I start making changes to the mail flow etc?

Any other quirky install features that you all know about would be appreciated

Thanks