As Fengwei pointed out in another thread, first reviews of the Tamron 18-250 are out, and it appears to be quite remarkable.
http://www.bobatkins.com/photography/reviews/tamron_18_250_1.html
So - go get one and post pictures and tell us how it works in practice
http://www.bobatkins.com/photography/reviews/tamron_18_250_1.html
So - go get one and post pictures and tell us how it works in practice