If they don't add them, and you're still craving the soundtracks:

http://dbsoundworks.bandcamp.com/ has a few Super Meat Boy soundtracks. You'll probably want the Digital Special Edition. (I physically have a signed Double CD copy, and it is glorious.)

http://spacerecordings.bandcamp.com/album/lone-survivor-orig... is the Lone Survivor soundtrack.

And the Braid soundtrack was linked elsewhere in the thread, but for completion's sake: http://magnatune.com/artists/braid

I've been listening to the Bastion soundtrack on repeat for the last week :-). I feel like it very much fits in the style of Firefly, but maybe that's just me.

The lyrical tracks are my favorite. Just fantastic music.

Especially Setting Sail, Coming Home (End Theme). Wonderful soundtrack.

I can't get Zia's song out of my head myself. Wonderfully done sound track.

I thought the same thing! Totally agree.

You can find the details of the Braid soundtrack here:

http://braid-game.com/news/2008/08/the-soundtrack-to-braid/

tl;dr version: it's all existing licensed music that the Braid guys don't have rights to distribute

That's actually out of date. Magnatune got all the music together for an album (with a great cover) they released later that year: http://magnatune.com/artists/braid

Edit: it was actually released in 2009, not 2008.

So they did, oops. Hopefully they'll add it to the Humble Bundle, then.