Just a thought!
Reserving my comments on whether an Immigration Officer will be convinced to let you enter UK on your current HSMP visa, but if your HSMP was approved before Dec-06 changes then you do not have to fulfil the new extension criteria imposed in Dec-06 (meet the 75 point requirement based on the various attributes). Read
HSMP JR - Policy document for details if you belong to the pre-Dec '06 approvals.
If you do belong to the category of people benefitting from the HSMP JR, you might still want to consider entering UK now, make efforts to become "economically active" in UK and take your chances when the time for extension comes (feb 2009).
regards