I'm seeing the same behavior on an Intel 320 series 300 GB SSD running Win 7 SP1. I tried two different Win7 images and tried in two different E6410 computers. The firmware is up-to-date. The fan tends to stay on and the power light never goes off. I don't have this problem with a standard mechanical drive.
I've since discovered that if I change the SATA mode from RAID to AHCI in the BIOS and *reinstall* Windows that everything functions normally.
For the record, before I reinstalled Windows 7, I tried the response at Changing from RAID to AHCI - Microsoft Answers marked as the "answer". This did allow me to change the mode without reinstalling Win7, but it only resolved the issue *sometimes*. The full reinstall completely corrected the problem, so far.
Hope this helps someone!
Let me amend my previous response. After turning BitLocker back on, I'm again seeing many times where the notebook won't power off, just as before. FWIW, if I put the old mechanical drive back in, I *never* have this problem, with or without BitLocker.