Obama strategist David Axelrod made the case today on "Morning Joe" (via The Page).
I don't see it as being a bigger deal per se--I'd say the Penn and Goolsbee meetings are basically a wash on their own terms.
Unlike Goolsbee (or at least the Goolsbee that emerges from the Canadian account), Penn didn't suggest Clinton wasn't sincere in her opposition to the Colombian trade pact. On the other hand, the mere presence of your chief strategist at such a meeting (as opposed to just a policy person) is a form of suggestion in itself.
What clinches it in Penn's favor is that he was on the Colombians' payroll. Clinton may really oppose the trade deal. But if someone as influential with her as Penn had a financial incentive to get it passed, that has implications for her position as a practical matter.
And, of course, it's hard to believe the Colombians would have ever hired Penn if not for his relationship with the Clintons. Which gets at the real problem with all of Penn's sleazy corporate dealings.