At present, RamJet, the only channels which have interactive contect (in langley areas) are Channel 4/E4 and Channel ntl:. Pressing red on BBC takes you to their walled garden site.
I expect that ntl: will be in discussions with $ky about providing the Sky Sports/News services to ntl: users, and the BBCi bridge was being tested last week so there should be BBC content soon. Give it a few months and you'll be in Red Button heaven!
Personally, I can make do with pressing back or TV when I don't want to see it. Broadcasters use it as an important tool for advertising their services and, as much as people may campiegn against the use of and red button advertising, I believe it is here to stay. I actually didin't notice it on E4 until one of my house-mates said "What's that in the corner of the screen?"!