On 'streaming' - my 2009 (HTPC) Mac Mini 2.26Ghz has no problem in 'streaming' BBC iPlayer, iTV Player, 4oD, Demand 5, SkyGo, or SeeSaw, for example.
It has no problem in streaming internet radio stations or audio/video podcasts via iTunes. What is more, downloaded movie rentals from iTunes is a doodle too - as is streaming achieved movies and music from my ReadyNAS. It all easily connects to my plasma panel and AVR.
As for control, sometimes I use a Logitech DiNovo Mini or Apple Magic TrackPad, or Harmony remote - and I plan on buying an iPod Touch to replace the lot (for HTPC and audio usage).