1080p encoding/decoding for 2 way video calls anyone?
ARM barely supports 1080p decoding, only one flavor.
This is just one example, there are many more.. Java anyone? -----
Yes, floating point does mater - and as ARM scales up, this will become much more important. This is the key CPU issue that Intel Atom supporters need to watch for. If ARM can scale this area (without killing battery) then Atom (until 20nm) is going to struggle.
Video encoding/decoding shouldn't be done on the CPU in a mobile device as it burns through battery (this would be true of Atom as well). On ARM cores with the SIMD instructions (not Tegra 2 which doesn't have them), ARM can decode HD streams without extra hardware support.
Java, probably a bad example as ARM outperforms Atom (Oak Trail) there as well (Android Honeycomb CaffeineMark). I admit, that the Intel benchmarks are unofficial and only for prototype tablets, so you would expect huge improvements (they need it, as they are really bad). We should see in the next few months as the first Intel Honeycomb tablets start arriving.