So, I'm playing Ashes Cricket and just for the lulz decided to see if custom soundtrack works and would you believe it...no, it suddenly occured to me that the last 4 games I played didn't have CS as well (InFamous, Uncharted 2, Pro evo 2010, Borderlands). A game like pro evolution, after you've played it for X amount of time, the soundtrack gets repeatative and annoying, making me want to turn off the volume, Whilst I understand it's not the be all and end all (personally I would like youtube uploading and in-game picture taking be made mandatory.) I do however believe this plays a big factor for some gamers, the ability to play your own music without resorting to an outside source. I'm told the 360 offers this as standard for the consoles so the devs don't have to do anything (please correct me if I'm wrong), since Sony for whatever reason can't match that, should they "force" devs to do it like that did with trophies? Or something else? 

I have had the complete opposite experience with custom soundtrack. The last 7 games I bought have had custom soundtrack:
1)Killzone 2

2) Flock

3) Burn Zombie Burn

4) Pixel Junk Shooter

5) Zombie Apocalypse

6) Final Fantasy Crystal Defenders

7) Astro Tripper

Though I have a ton more that support the feature, I do have some games that I wish did support it as well (condemn 2, Chronicles of Riddick, Mercenaries 2, & Mirrors Edge).

This might be a limiting factor for PS3-- developers might not appreciate it until the PS3 catches up to 360 to a greater degree

That's another point I forgot to mention, Sony's own first party games don't seem to be 100% behind it as well, e.g Uncharted 2 sure U2's soundtrack is amazing and custom soundtrack defeats the purpose of single player storyline but what about online?

You pointed out K2 but the rest of your list is mostly psn stuff, I've noticed this is more common with disc games than psn ones, any ideas why the refusal to support it?

Should I be allowed more options to play my game... who's going to say no? I love custom soundtracks.

YEEEEEEEEEEEEEEEES! MAKE IT MANDATORY!

It is probably easier for PSN games due to there reliance on the HDD then disc based games.  Maybe it is just not that important to developers to support this feature.  MLB 09, NBA, and Warhawk which are first party games do support the feature;  I do believe that the smack down games also support this feature.  It is weird now that I think about it.

Wow you are not even trying to hide your bias.  I do not think this has anything to do with it, especially because they are so close in sales.  But nice try though.

Yes, that would be lovely.

No, i'm just being honest and if anything, i'm a PS3 fanboy.  However, it's just obvious that sony doesn't have as much power over 3rd party developers as it will than say at the end of the year so perhaps they are being easier with some of the rules.