Absolutely. The only issue you lose is load time validation. If you try to use a dynamic pool name that isn't defined in the configuration, you'll get a runtime error causing the connection to abort. You'll want to enclose your pool command with a "catch" statement to ensure that the runtime error doesn't occur and if it does either assign a default pool, redirect the user somewhere, or use an HTTP::respond to return status content directly to the client.
Here's a post on the "catch" statement:
http://devcentral.f5.com/Default.aspx?tabid=53&view=topic&forumid=5&postid=10280
Click here
-Joe
Nimbostratus