I am really into the David Hattner series of videos. Stellar resource: http://www.youtube.com/results?search_query=David+Hattner&search=Search Turn up the volume and enjoy.
I discovered the Buzzing Read blog and although there could be a lot more I’ve loving what I find like the topic Organic Rhythm.

"Great musicians can play a phrase of music with incredible rhythmic accuracy, and yet never quite match up with a metronome. Great chamber groups and even whole orchestras can do the same. It’s obviously a lot harder for the latter, but with years of experience and trust among players, a larger group can be free and stay together rhythmically.

One form of freedom is called “rubato”, which means “to steal or borrow” time from one part of the phrase to add to another. The total sum of time is the same as the metronomic phrase, but with much greater freedom. That kind of phrasing says keeps the listener interested with its unpredictable freedom. The player can then emphasize the natural tension and relaxation and explore the infinite possibilities with each repeated phrase or section of music."