Google Reader is Google's RSS/Atom/XML-flavor-of-the-moment feed aggregator, with support for OPML import.
It now has passable support for mobile devices (and even the "Wii":Wii), and the usual Google KISS design, Ajaxy bits and good usability (including the usual vim keybindings for the geek crowd).
Sadly, it does not support any kind of automated filtering (or classification) whatsoever.