[Rigel]

Also, even assuming SWIFT won't let the feds search through their database for info on individual wire transfers, will that prevent the feds from telling US banks "we ask for you to voluntarily agree not to send wires to or accept wires from this particular desination, (e.g. Pokerstar's bank)."?

Banks are very risk-averse and the subpoenas served on Deustche bank and other banks has no doubt got their attention. So I would imagine that, however secretive individual wire transfers may be, the Feds could easily pressure banks into just not permitting transfers at all to or from poker sites.