Not that my preferences really mean a hill of beans to anyone else, but since I've asked for your vote on my sessions, I'd also like to share the list of sessions that I've marked as "preferred" so far. Now, since we have no idea what the schedule will be, we can pick and choose the sessions without any concern about who's up against who in the same time slot; we can leave that agony for the day the schedule is released. In the meantime, you can pick the sessions you'd like to see, in an ideal world with no conflicts!
I doubt I will have the opportunity to attend any pre-cons, but if I did, here are the two that would most likely end in some arbitrary tie-breaker:
Future Diagnostic improvements in Denali 
Microsoft CSS Team (blog)
Regular sessions & spotlights
These are the top 10 that stood out to me, in no particular order. Some I chose because I really enjoy sessions by these people, others I chose because I am very interested in the topic or I feel the need for a refresher.
100 Years of Transaction solitude 
Ami Levin (twitter)
PDW Architecture and Internals 
Richard Waymire, Brian Walker
SQL Server Execution Plans – From Compilation To Caching To Reuse 
Maciej Pilecki (twitter)
If you want to mark sessions as preferences, please visit the PASS web site (login required).