There are new technologies on the horizon, yes. But they are still very expensive, and it would be a long time till they trickle down to being mainstream. There is also no real definitive next best technology path that seems to be the way all TV's will go.
TV's are always releasing new models month after month, holding off for the next best thing to be released in the near future will only make you wait and wait and wait. You'd might as well buy what you can now(ish)
That being said, dont be jumping in to the first thing you see, if your old TV is still working, then take the time to look around and see whats out there and see what you need and like. There are big differences in picture quality between makes and models.
There is also the issue of what you are going to feed the TV with in terms of a signal … again, that makes big differences to the picture quality, so look into that too … even a better cable for the sake of £10 over a cheaper cable can make pictures look better.
Personally, if i was going for a TV these days I would want as a minimum
native 1080p ability ( 1920×1080 resolution basically )
LCD ( or LED, but thats out your budget )
HDMI or some other digital inputs ( display port etc )