The Third Circuit Court of Appeals has held in United States v. Orocio that Padilla announced an “old rule” and can therefore be applied retroactively. Although this was a 2-1 decision, the dissenting judge only took issue with the majority’s Strickland prejudice analysis.
In ruling that Padilla announced an “old rule” the Orocio court focused on Strickland’s bedrock standard of “reasonableness” under the circumstances. It matters not then that Strickland would eventually be applied to potentially novel factual circumstances. What matters is that the reviewing court looked to the reasonableness standard in determining whether there was a viable ineffective assistance of counsel claim. This is precisely what the Supreme Court did in Padilla.
The decision can be downloaded here.