MPEG 4 is an excellent format; it provides high compression, and potentially high-fidelity video. The popularity of DivX (one of the implementations of MPEG 4) shows how important this technology is. However, it has some limitations - It requires considerably more processing power, both to encode and decode, and is less tolerant to corruption.
Its use as a format in a digital video recorder was suggested earlier - but this is unlikely to be a commercial success - MPEG 2 is perfectly adequate and storage capacity is extremely cheap. Additionally, in Europe, where digital broadcasting is well established, the preferred format is MPEG 2. Commercially available combination receivers/DVRs simply save the raw MPEG2 stream to disk, and replay it when required. The additional expense of a transcoder would far exceed the saving in terms of storage capacity.
For broadcast purposes MPEG2 is far superior to MPEG4 - as the former is tolerant to minor corruptions and dropouts. The same features are also useful in optical disc players, where dust and fingerprints can cause similar problems with reading. A change to a higher compression ratio, often requires a higher error correction level (with subsequent reduction in available capacity). This is one reason why digital radio is broadcast in layer 2 (MP2) rather than layer 3 (MP3). After allowing for error correction, MP3 offers very little advantage over MP2 - and requires significantly more processing.
Current DVD-R/RW technology can store about 2 hours of footage on a single disc in very satisfactory quality (better than some broadcasts). Future advances in storage are likely to improve this more than a change in codec, with less associated complexity.
Facebook
Twitter