I'll be perfectly honest, I wouldn't get my hopes up too high on a big rebate for the 5D. In the last couple of days, the 5D's price has been dropped about $300 and it is selling for $2299. As much as I would like it to, I doubt Canon will throw on a $600 double rebate on top of that like they did last year. I'm execting about a $150 rebate, or $300 double rebate to get the price to $1999. This will kill the used market for 5D's as they are sellinng for $2000-2100 used. Within 6 months I think you will start seeing used 5D's hit the $1500 range.
People will want to base the US rebates on the Canadian rebates, however I think that is a poor basis, as the 5D sell for SO much more in Canada than in the US. As a result, the rebates will be much larger than in the US in my opinion.
Given the recent moves, I think it is almost 100% guaranteed that we will see the 5D successor announced in January at PMA.
I'm going to get the 5D come October 15, when the rebates come out. As much as I would like to have the successor, I can't fathom paying $3000+ for a camera. I'm having a difficulty talking myself into paying $2300 for a camera body. The price drop with upcoming rebates put the camera in my reach, and despite what the successor may offer, the 5D will still take fantastic pictures.