Wirelessly posted (Mozilla/5.0 (iPod; U; CPU iPhone OS 4_1 like Mac OS X; en-us) AppleWebKit/532.9 (KHTML, like Gecko) Version/4.0.5 Mobile/8B117 Safari/6531.22.7)
2007-2008 30 pin to USB was slow.
2008-2009 I think, in iOS 3 they decreased how long it took to sync.
2009-2010 iOS4 syncing is slightly faster than iOS3.
2010-2011 I think they'll introduce Light Peak in their Macs; however, as people have already said, Apple will need to put in "faster" SSD's in their iDevices to even be bottlenecked by USB 2.0, no matter about USB 3.0 and Light Peak.
2011 - 2012 I think this is when cloud iTunes is introduced and wireless syncing; however, you still control you music and movies on iTunes and only in your home.
2012 + "full" wireless syncing is introduced; I don't know how Apple will do it, but I think that you will be able to sync anywhere there is wifi or 3G.