Question : Moving to Exchange 2010 from Exchange 2007

We have been running exchange 2007 on a windows 2003 x64 server vm the past few years and want to upgrade to exchange 2010.

I built a new VM with Server 2008 and have loaded Exchange 2010 on a seperate VM host.

My questions are:

-is it possible to export the AD from server 2003 to new exchange vm running Server 08, or would that be problematic?

-Is it possible to export the Exchange databases from 2007 and import into 2010 or is it easier to just upload PST files?  If this is done, will mailboxes be recreated?

-Can I use the same cert from exchange 2007 if the server name & domain is the same, or does Exchange 2010 require a different type of cert?

I have a feeling that a clean install to exchange 2010 and recreating AD & Mailboxes and uploading PST's for mailbox data is best way to go - but wanted to see if anyone had any luck with the above if its even possible.

Answer : Moving to Exchange 2010 from Exchange 2007

You can synch multiple calendars but only one Exchange calendar.

For example, if you have a yahoo, gmail and exchange account you can have all three calendars synchronised (using BES and BIS).