I'm kinda with Celb on this one. I hardly ever use that feature on my 360. But it's still nice to know it's there....just in case.

I wonder if you can use that feature while playing a ps1 or ps2 game?

Its coming out next week, comfirmed by a sony employe at the ps blog. Though he just said a firmware update not specificly 1.90

Nice. I look forward to this.

While I do agree that music has an integral role in the artists tools for the development of their overall desires within a game ( just as John Carpenter about what music did for him), I also think that most game music these days is forgettable.

So having the ability to put on some groovy tunes while pulling out the whooping stick is far from a bad thing in my opinion.

I agree.  I'd also like some in-game music in Super Stardust and other such games. 

It is especially cool for online play, racing, puzzle and games with no music (Gran Turismo HD Concept)