When I buy hardware I always assume that it will get obsolete very fast. Therefore, I take the deal that involves less upfront $$$, in this case leasing. Anyway, that's jus my opinion.
The cable companies are targeting the upgrade fees and so forth right now (at least the cable company in my area). Personally I would not pay $250 to lease a receiver that I would never own unless promised free upgrades for now on (or every x numbero f years) and a lifetime warranty. I would wait for the new HD DVR receiver (rumored to be the 962 receiver that is the same as the 942 only with MPEG-4 capability).