I waited to comment on the 18-200 until I saw pricing, I thought maybe they were going to kill the 55-250, since it's on backorder in Canada. Then the no USM thing would make sense.
I can see the logic in not wanting to cannibalize higher end EF-S & L lens sales with a kick butt superzoom (like the 28-300L). I know for a fact Nikon has lost additional lens sales because of the “do it all” lens.
Now Canon has priced what appears to be a plastic fantastic lens almost to where the well built (other than the barrel creep) Nikon is. Adding an Ultrasonic Motor can't cost that much, it's been around forever.
Perception seems to say Canon has really dropped the ball on this thing if pricing is correct.
Canon Canada Pricing MSRP
50D Body Only – $1449
50D w/17-85 IS – $1799
50D w/18-200 IS – $2049
18-200 f/3.5-5.6 IS – $749 (No USM?)
A1000 – $229
A2000 – $259
SX110 – $299
E1 – $229 (Huh?)
B&H Pricing on the 50D