with regard to the '5 years' time scale, I think its 5 years before HD will be fully phased into the UK, with terrestrial (BBC, ITV) and digital channels (Sky, etc) gradually switching to hi-def broadcasting.
I have recently seen televisions in the UK advertised as 'HD ready', but it seems a while until it becomes a standard over here.
you can still hook your X360 upto a normal TV, it just won't look as good as if it were plugged into a HD set - a good idea, as outlined previsouly, would be to get a VGA box used in conjunction with your computer monitor until it comes time to buy a nice big HD Tv set... Whyyy is everything soo cheap and so much more advanced in america??
I was in fact visiting some friends in the USA last week, they got a reeeally nice sony 60" LCD (High Definition, by the way), for $4000! that is like £2300! I doubt you can get a sony NON-HD plasma for that much over here... aaargh, the frustration..
enough rambling... just get an xbox 360 with a vga box, and when HD becomes cheaper, or you find a good offer (6 months to a year later?), splash out on a HDTV, that is def. what im going to do.
-Ehosin