That's a really great idea. I always enjoy reading in-depth criticism of people's works, and am glad that something like that can be done in the Poetry section.
My suggestion is that instead of having one thread where people post the poems they want reviewed by these "special reviewers", it would be much neater to put the information about the reviewers in a sticky thread, so that way posters can look for a reviewer that reviews in a style they like, and request a review. (Run-on sentence away!) This way, the reviews for a particular poem are kept in one thread so the poster doesn't have to go looking for the reviews that apply to their poem. Also, it would be easier for the reviewers to find the poems that were requested to be reviewed.
Just my thoughts on it, but I still think that this is a great idea.