Ben Witherington just published a commentary on 1 and 2 Thessalonians, published October 30th, 2006. I haven’t been able to get my hands on it yet because it’s currently only in a few libraries in the whole country. I did find the TOC on Baker Book House’s web site. Here’s his rhetorical analysis of 1 Thessalonians:

Prescript 1:1
Exordium 1:2-3
Narratio 1:4-3:10
Transitus 3:11-13
Exhortatio 4:1-5:15
Part I 4:1-8, 9-12
Part II 4:13-5:11
Part III 5:12-15
Peroratio 5:16-22
Invocation 5:23-24
Epistolary Closing 5:25-28