Ok, I guess we have to step in here!
First of all, performance is and will always be one of our top priorities. We are usually forced to divert efforts away from performance improvements and into other features, but anything that could hurt performance is examined up close to make sure we're never slower than we were before.
As I'm writing this, we're giving the final touches to a time profiler system that allows us to check exactly on what sections of our code the CPU is stalled or unreasonably busy. This should help us enormously to track down performance problems.
However, just as Arima says, there are some things that are beyond our control, like hardware capabilities.
Android devices are getting quite good now, but most of the ones from 1-2 years ago have embarrassingly low specs compared to the iOS ones.
Also, the operating system itself is getting really fast now after "project butter", but Android 2.x is about as slow as you can possibly get for an OS. We've seen the same hardware going from 30 to 60 fps just because of an OS update :-
So, to sum it up, we'll keep doing our best to be as fast as physically possible. Miracles might take a bit longer to achieve ;-)