I went shopping on line today for the 300 D AFS. Everyone is back-ordered right now. Only Adorama has grey market lenses @ $1,169. The best that I can tell about the difference between grey and regular is that regular comes with a 5 year warranty, grey comes only with Adorama's own 1 year warranty. Although Adorama sells an additional 7 years for $34.95 under "Mack".
Unless you strongly advise me otherwise, I will buy the grey in a day or two. Not to save the money, but because I'm afraid I'll miss a chunk of bird season before the regular lenses hit the stores.