Not a lawyer, but I highly doubt it. DMCA allows someone who clearly owns a copyright to request that unauthorized material--that individual (or entity) is the only party that has standing. One of the central issues with enforcing GPL is that ownership of the IP is ambiguous.

As for "public interest" lawyers... they go where there is money to be made in a judgment/settlement. Amazon publishes the Kindle source code because they've got deep pockets and are likely to continue to exist over the next decade. In other words, they made a business decision that it was more prudent to make their code freely available because they that the expected losses from competitors seeing their code was less than the costs associated with defending themselves against a suit. There isn't going to be a lot of interest in enTourage at this point because, well, frankly they don't have the assets to make it worth anyone's while. A fairly well-known case against Cisco infringing on GPL for router firmware took over six years to settle... the law firm stuck with it because they were reasonably certain that a company as well-established as Cisco would be a going concern and would have the resources to fund an eventual settlement. A startup company has a certain advantage over established firms in that law firms have to substantially discount the net expected payout of a settlement by the chance that the startup will still be around if/when the case is settled in their favor. I don't think is a parasitic attorney out there who looks at a one year-old startup trying to compete in a very competitive market against Goliaths like Amazon, ASUS, Apple, etc. and thinks "There's money to made in a protracted lawsuit over ambiguous case law."

If/when the various issues regarding the full extent of the GPL are definitively resolved (i.e., a series of SCOTUS decisions), it will involve companies with the resources more along the lines of a Cisco than enTourage.