I'll let you know how ours is when it comes in. I dropped about $2500 on one with accessories last night (including a 4 gig Nano, spare battery, maxed out white model). The shipping date is early June. Hopefully they won't wait until the battery is available to ship it, they won't have spare batteries available until June 13.
There will be photos and a write-up. I may also try boot camp on it but we'll see how the wife feels about that, since it is her graduation present.
Sentinel.SYS does appear to be a valid Windows process. I don't know whether you have to have it running, but it doesn't appear to be harmful. It's made by Rainbow Technologies. It looks like the software that runs a hardlock dongle: