EULA is regarded as a contract in "most" (or all?) jurisdictions, and as such, depend on contract law to define what is allow and what isn't. EULA's is also regulated under consumer protection laws. Since each state in the USA have slightly different kind of consumer protection and contract law, one would really need to dig down into the law books to decide if the EULA is at all legally binding in a specific state.
But I have one correction to mention. Copyright licenses are not viewed as contract in the USA. Copyright licenses like GPL are granted permissions, waiving the right to sue distributors under specific situation. If the distributor get sued for distributing GPL software, then it is she who must raise the license as protection. "I got right to distribute this copyrighted work, because I received this license who says I can". The license "terms" only specifies under what situation permission have been given.
In EU however, licenses are contract and under contract law. As such, the permission to distribute can be revoked if contract law has been violated.
At least for me any EULAs that aren't signed before purchase (i.e., all shrinkwrap or clickthrough "agreements") aren't binding unless I choose to - B2B sales with explicit signed contracts would be binding; or if I want to do something that by law requires permission (i.e., redistribution instead of just using the software) then I might accept an 'EULA' such as GPL.