BPEL Analysts

Four Star Resources

Gartner
Gartner covers BPEL from many perspectives, including applications, process management, integration and infrastructure
Source: Gartner

Three Star Resources

ZapThink
ZapThink focuses on Services Oriented Integration, of which BPEL is a key component
Source: ZapThink

Forrester Research
A few quotes from two Forrester Research analysts. Worthwhile reading.
Source: Forrester Research