I'd say its well worth it. As Gammon notes pitching is at a premium and I think we can get a lot for Lee even with him having a bad half.
I bet we could get Griffey for Cliff Lee, assuming he has a few decent starts between now and then, and FGutz and a low level prospect.
This trade would give us a rotation of...
And a lineup of
With Jbarf and Michaels/Fransico switching between the 2 hole and the 9 hole.
That looks like an upgrade well worth making to me.