The endorsement in the passport will be Tier 1 only, irrespective of whether one applies under old pre-Dec '06 HSMP rules or the post-Dec'06 / Tier 1 rules. At the most (and I am guessing here), for applications approved from 17-July onwards the endorsement might state Tier 1 (HSMP) rather than Tier 1 (General) - perhaps just to make it easier to differentiate between pre-Dec '06 and post-Dec'06 HSMP / Tier 1 approvals by looking at the visa!
The Tier 1 sticker in your passport doesn't take away your rights (whichever you wish to enjoy) as a HSMP visa holder. Reading
this might offer some reassurance.
regards