My general plea regarding any new merchandise is that you release items that are companion themed.
1. Mobile Phone ringtones and wallpaper - yes it's easy enough to take a screenshot in game and use that but I'd rather have something that didn't look like I'd done that and that included the DA logo (the companions please, not their concept art or the origin character wallpaper). Ringtones too - bundle some of the dialogues from each character and sell them as a pack (so, for say, .99 we get 5 different choices from one character - there'd be a Zevran pack and an Alistair pack... okay fine, a Morrigan pack too. And who wouldn't want Sten on their phone saying: I was told there would be cake. The cake is a lie.).
2. More companion themed gear (everyone seems to love the hoodies, and maybe it's just me because I don't wear them, so I'd prefer t-shirts). You can find some of these on sites like Cafe Press and the ones that are offered are actually pretty good (using quotes of the dialogue), but I have to choose where to spend my money, I'd prefer it go to Bioware.
3. I agree with what someone posted above, mix it up a little. Keychains, stickers/bumperstickers (I'd say pins or patches but I have nothing I'd ever be able to patch or pin any of it to), those silicon bracelets (Team Zevran, Team Alistair, GO), mousepads, posters (although the lithographs that get offered are very nice, they're nothing I'd personally buy).