Several solutions are available & according to a study from ABI Research , collectively they will account for some $80 billion worldwide in investment over the next 5 years.

“Cable TV operators trying to satisfy the increasing bandwidth demands of  HDTV customers feel very much like the thrifty grocer who tried to cram ten pounds of potatoes into a five-pound bag,” says vice president and research director Stan Schatt.

Shaping & expanding spectrum beyond 750 MHz technologies have already been undertaken by some cable operators (particularly in the US) Other  tehnologies are spectrum upgrades coupled with node-splitting, switched digital video, MPEG-4 compression, PON overlay & home gateway bandwidth management solutions (like QOS)

“The increasing bandwidth demands on cable operators will soon reach crisis stage, yet this is a ‘dirty little industry secret’ that no one talks about” according to Stan Schatt.

This problem was also noted by several companies a year ago, according to an article in the USA Today

European cable companies are at this moment very slow with introducing HDTV to their subscribers, because they also note a significant increase in bandwidth usage & aren't really prepared for this increasement.