Lifetime TiVo service is no longer offered on the DirecTiVo units. However, they cut the monthly fee down to something like $5/month. You'd have to be keeping the box for a long time before the lifetime sub became worthwhile.

As to the HD-DirecTiVo, there's much speculation on the matter of its release date. They had a prototype at the last CES and they claim they'll have it out in time for Christmas. A friend and I have a small wager riding on whether they pull it off. Here's the original press release.