Forget MPEG4 for at least 5-8years anyway. Many people don't even have digital yet, the transition from analogue to digital has taken 9 years, all up will take over 10 years! So expect simulcast MPEG2/MPEG4 in a number of years time as many people don't have equipment capable of MPEG4.
Beyonwiz are offering this because to stay in the business of selling PVRs, they have to provide something with a Freeview sticker on it as people (and retailers) are asking for something with a freeview sticker. Freeview has an extra set of requirements beyond what digital today offers, and has an extra set of "rules". Rules like you can't jump skip a period of time, e.g. to skip tv commercials. But requirements include a potentially feature rich EPG where you don't have to surf all the channels to get it data filled (you don't anyway if you use ICE.... but if you use FTA guides at the moment you do), will look the same for all Freeview stickered boxes (so when someone with BoxX talks about pressing the red button, it will do the same thing and look the same between all brands). Features like over the air firmware upgrading (this is supported now for many boxes, but trying to get all the broadcasters to carry your 8megabyte firmware image for Brand X is nearly impossible, unless you are LG with a lot of face to save because of a giant bug in your TV software etc).
Freeview hasn't revealed all that much information of substance anyway, so if you can dig thru the FUD you will see that it is a lot about marketing a product to keep the advertisers happy (no advert skipping), while trying to get more people across to digital on the promise of a fantastic set of extra channels (FUD because this is available now.... and in the case of Ten with ONE, they didn't really give us much extra, still only 2 channels just like before, and we lose all our fave drama/sci-fi/doco's in HD too... grr). Freeview is really just the TV industry trying to homogenise the digital experience for everyone, and try to do something to stop the bleeding.
Regards