How important is backward compatibility in truth?

[SSJGohan3972]

I picked up a Wii with one of the large considering factors being backwards compatability (I had not had a console during the PS2/GCN/XB gen although I eventually did pickup a PS2)

I got the Wii U with backwards compatability being a large factor (I do not want two consoles on my main TV and was able to give my Wii to my sister who bought several more games for it - a win-win for Nintendo)

I was considering picking up a PS4 because I (I think like most gamers) am always intrigued by each new generation but without backwards compatability I decided my best bet would be to pickup a PS3 instead (did so about two weeks ago, didn't wait for the anouncement as I knew after a little research that the Cell would not make BC practical) and wait until the PS4 has been out for a few years before picking it up (once the library gets some weight).

The XBox has the same considerations, I want one as I want to branch out to more and more gaming. If the Next XBox has BC I will get it and pickup a bunch of 360 games for it (and it would most likely delay my PS4 purchase a year or two), if not I will probably pickup a 360 around this time next year and play the backlog (and not pickup the next XBox until about the end of the gen).

Also I am thinking about getting a PSP (and have been for a few years really) but I can't quite make the jump, had the PSVita been fully backwards compatible I would have one in my possession right now - alas I do not (apparently it has some form but not that good, not sure)