It is a toss-up between the Rotel amps and the Dynaudio speakers.
If that is the case I would suggest that you stay put and don't do anything. It is a vicious cycle as once you start to change one component in your system you would start looking at the next. Having said that, if you really have the urge of improving your system and want to get a little bit more out of it, I would suggest to go with your initial plan that is to go with a speaker upgrade. Although the Rotel amps may be mid-fi, a different speaker will yield a more significant impact in sound improvement compared to a change in amps. If looking at a different speaker, I would suggest getting one that has bigger drivers in comparison to your existing Dynaudio 52SE that your room can accomodate. Speakers with bigger drivers will always sound more full and coherent compared to equivalent speakers with smaller drivers. You only need to decide whether you would still want to stick back to the Dynaudio line or consider other brand of speakers.
07-03-09: Miner42
After a lengthy listen last night I really don't kow what I could do to improve - I was very pleased with results.