Antoine is currently testing Vienna aggregator. It looks quite nice, in some way similar to Shrook that I've bought some months ago.
I'm happy with Shrook, however there are things I dislike (mainly feature opacity (closed source), memory consumption, high CPU usage)... so GPL'd (?) challengers are welcome! (any good one in Perl ? ;)
But for now memory consumption of Vienna seems to be even higher than shrook (higher than Firefox 1.5 even)