Someday, hopefully at least a year or 2 away, I will have to pay to upgrade one or both of my SD receivers (or go without), lose my grandfathered DVR status and start paying more DVR fees (no point in having a non-DVR receiver, in my view, unless the external storage works with ViP211/222), and maybe also pay to reaim a satellite dish. I'm very happy with Dish, but there are limits.
I guess I'd better start recording stuff off the 721 and 508 now, onto DVD.
Of course, if my bedroom SDTV dies, moving up to an HDTV is a no brainer. Then I decide to replace an SD receiver with a ViP, or just set up the ViP622 in dual mode. But then, the transition would be on my schedule, not because I'm forced into it.
I believe Dish will keep HD on the current satellites, at least for another year and probably longer. Too many people would be forced to move with too little notice if they only had HD on new sat locations, and SD receivers would have to be dumped. Of course, I could also put up a dish farm on my roof.