I think right now they aren't using Alex Riley to his full potential. If I was the booker, I would book him against Daniel Bryan in tag matches, handicap matches, and things of that nature, and then eventually at a pay-per-view like Survivor Series or something, Daniel Bryan can go one-on-one with Alex Riley. Riley can lose, Miz can bitch him out, and Riley can turn on Miz, become a face, and then start wrestling in the midcard section of the shows, whilst many feuds by then would be over, and Daniel Bryan will have better options in terms of potential feuds.
This way, Riley gets over, we get a break from Miz and Bryan, yet can still emphasize how much Cole wants Miz's nuts and Riley's nuts, we show off Riley's talent, show off Bryan's talent, get Bryan over, get Riley over, get Miz over, keep Miz busy but not the primary priority in a singles feud, all the while give 'em all something to do for two months until slots for a feud are opened.
They dropped the ball on a feud with Morrison already. That's not going to happen.
If CM Punk comes and feuds with Daniel Bryan, it would be kind of crappy, promo-wise. Bryan doesn't have the skills to improvise enough to find something wrong with CM Punk, other than the typical "You're a heel" b.s. Punk is great on the mic, but Bryan doesn't drink, smoke, or anything like that, not to mention he's not fat, or doesn't have any obvious issue that everyone can point out easily, and Punk usually feuds with someone who is fat, or who is legitimately weird, or someone who drinks or all in all, isn't straight edge.
It'd be shitty build-up, it'd waste Punk's talents, ruin his push, put him on a show where he's definitely not gonna' be main eventing, EVER, and will probably make people become bored of Daniel Bryan, whilst Miz and Riley have nothing to do and they'll just be card-fillers, and don't do anything special either, which would also become boring after another couple of weeks.
Think about it, 'yo.