I am sure some people will be in for a letdown because I've read some pretty outlandish expectations on this forum.
Based on the specs that are being rumored, I expect we'll see a 22mp camera with a very nice autofocus system priced at around $3,000. Some modest improvements in high ISO noise but not at the level of the 1Dx. As a bonus, it may have some modest weathersealing, similar to the current 7D and maybe a new accessory battery grip with an extra control wheel.
I don't think reasonable people will be disappointed with that. But, for those who want a baby 1Dx for the price of a 7D, they will likely be all over this forum the day the camera is announced, complaining how Canon doesn't care about them and they are going to go buy a Nikon.