Contrary to earlier news reports, VR-Zone claims that Intel's new WW04 roadmaps indicate that the Penryn doesn't support HT and that the Nehalem doesn't support it either:
Someone has unknowingly put a tick to Yorkfield and Wolfdale at the Hyper-Threading column but the number of core/threads still remains at 4/4 and 2/2 respectively. Anyway, the air is cleared and the finalized roadmap is correctly reflected that Penryn will not support HT neither do Nehalem. Intel will use a new term called MTT for Nehalem and Nehalem-C.