A month of almost continuous cricket, too much? Hell, no!
I think this is a very fair system -- at the start, every team had their chance, and not one single team was knocked out by one freak result. Pak just needed to beat Ireland to stay in, while India could have beaten SL.
The best 8 teams in the tournament
during the group stage have ended up in the Super 8. And now, each team gets to test itself against all the others.
There really haven't been that many dead rubbers so far, although there may be a couple around the corner. And all the minnows got at least three matches against decent opposition.
The only fair alternative I can think of would be to have a "Super 2x4" phase, with two groups of four (e.g. SuperA=A1/B2/C1/D2, SuperB=A2/B1/C2/D1) and only then go into the semi-finals (SuperA1 vs SuperB2, SuperA2 vs SuperB1).