If you're not sure how to flash this Disturb3d1 has made a great video showing how to update.
These must be flashed through the Recovery.
Note About Mods: Since this update is Android 2.3.4, while the old one was 2.3.3, all of the framework mods will need to be remade for this version. Using any of the old ones will cause issues and could make the ROM unstable.
Stock 2.08.651.2 With HTC/Sprint Spyware Removed
[ROM] Stock 2.08.651.2 With HTC/Sprint Spyware Removed
These must be flashed through fastboot/hboot.
Rmk40 from the Sensation side has a thread containing info about the different partitions here. At the moment it looks like the radio, rcdata and RPM partitions are the only ones of use to us, but you should be fine if you decide to update everything else as well. Also, if you need an easy way to check MD5 sums you can find a windoze tool for it here(Thx riggsAndroid!).
Full 2.08.651.2 Firmware Zip Extracted From The RUU
This is mainly for devs but it can also be used to restore your phone if needed. Flashing it will restore your phone to a completely stock state and will wipe everything!
PG86IMG_2.08.651.2.zip (MD5: 29F1698BCBF478A7297703D812718D35)
All of the PG86IMGs below are included in PG86IMG_2.08.651.2_firmware_nohboot.zip.
Radio & PRI Updates Radio 0.97.10.0808 PRI 1.24_003
PG86IMG_radio_pri.zip (MD5: E28414AAC6F91CE9D7B3615B2999AD3A)
RPM Possible fix for Black SOD
PG86IMG_rpm.zip (MD5: DE69396C8922FAD3AC82E5F836EE95FB)
SBL Secure/Secondary Bootloader?
PG86IMG_sbl.zip (MD5: 5604349AD611241CF1AC152FD3B0DE45)
TZ Trusted Zone - Not sure of it's purpose
PG86IMG_tz.zip (MD5: 75749FBCCE1331A5A85D2A154E15B276)
PG2F2_SPCUSTOM - No idea what it is
PG86IMG_pg2f2_spcustom.zip (MD5: 7A7DE8659A0771919A14B0C299CA18CC)
dsixda for all of the hard work he's put into his ROM kitchen and for updating it for us
NewZJ for testing the firmware and posting the new Radio and PRI versions
luckylui for researching the different partition types
riggsAndroid for the link to the MD5 prog
rmk40 for his thread over in the Sensation forum about the different partitions
Football for sharing the 2.08.651.2 RUU
disturb3d for his videos about 2.08.641.1 and for the heads up about Wifi Tether
mikeyxda for his guide on how to update with this
donatom3 for helping clarify about Firmware and the ROM