Napster wasn't illegal per se. However, it did enable bad little boys and girls to violate copyrights and acquire music libraries without paying for them. It was the old "something for nothing" scam with a middle-man profiting from the illegal transactions. The basic technology was, oh, maybe 20 years old.
Neteller is/was also an enabler, but in the financial realm. It enabled users to move money from domestic (regulated) institutions offshore to (unregulated, by the US) gaming institutions. Stable "workarounds" (as inappropriately illustrated by the Napster follow-on) aren't going to happen because there already exists a body of laws and regulations, both domestic (UIGEA is only the most recent) and international, to prevent it. Which leads me to
See:
http://drsanity.blogspot.com/2007/02...of-denial.html
for a good explanation of the denial mechanism (in another context). Sorry I couldn't find one specific to poker. Ignore the politics and focus on the general descriptive material.
And finally: Re state vs federal rights. If it (for very broad definitions of it) crosses state or national boundaries, the federal government can, and frequently does, get involved. This country (the US) was set up so that any rights not specifically granted to the federal government were implicitly granted to the states. That fundamental went by the wayside long ago, and the trend continues. An amazing number of laws exist under the umbrella of (interstate) commerce, for example, and there's nothing concrete to suggest that the Feds wouldn't become involved if domestic interstate online poker ever became a reality - which it could any day. This is not to suggest it would be banned, but it sure as hell would be monitored and regulated in some manner, as would the "enabling" businesses.