What do these have to do with each other. Just because a channel(s) is in MPEG4, does NOT mean D* has to give it to you in HD for FREE.
Look at all the MPEG4 local markets - those locals are put up in HD only, but unless you have HD access on your account, you can watch them ONLY in SD.
BTW, I don't know where people keep coming up with this, but they will NOT be switching ALL channels to MPEG4 "soon". There are too many SD only receivers out there now - not to mention the fact that D* is STILL installing MPEG2 SD receivers in most local markets for SD only subs, so this should give you a clue how fast everything will be MPEG4...