I have moved to Lion coupled with Parallels 7 and would like to give a bit of warning if all goes well in the migration.
Do NOT modify the disk partions using OS X disk utility. Any change to the partition table can (and most likely will) cause your Windows partition to be destroyed both the VM, if you are using Parallels, and Boot Camp.
I have spent many hours reinstalling Windows because of this very issue. So as digitxp said, expect the worse. I just hope to help highlight what the worst could be.
Not sure why I did not include this in my answer before. Regarding modifying the disk partions. If you change them before running Boot Camp, Boot Camp will fail and make you create a single partition for OS X before you can continue. In addition if you change the partitions after installing Windows, it will destroy the Windows partition. The only way that I have seen to create multiple partitions with Lion and Boot Camp can be found here at apple.stackexchange.com.