Good issues to consider. I'm not a lawyer but I deal with this sort of stuff, so here's my projected worst case scenario:

Domain: Epic Duels is a game that has been out of production for a number of years, but it is without question the intellectual property of Hasbro, and it's int prop used under license from Lucas vis Star Wars, so it probably cost them rather a lot. It's entirely likely that Hasbro would send a cease and desist letter, and if they did we'd have no choice but to relinquish the domain since they own the trademark. Historically Hasbro has defended their property fairly aggressively - for instance, they went after a teenage kid because he registered Dynobot.org, despite the fact that he'd been using it as his online gaming handled for years and that it was spelled differently than Dinobot, which is the relevant Hasbro trademark.

That said...Epic Duels is obviously not the crown jewel in the Hasbro library, so provided that we don't charge anything for anything in any sort of relation to the site, provided that we make it very clear on every page and in every download that it's being done without permission or approval from Hasbro, and provided that we never include anything questionable (no naked slave leia decks, and probably no Holiday Special expansion) then there's at least a 50/50 chance they'll just quietly ignore us, as nothing we're doing is costing them money and letting us do our thing increases their reputation as a good will company.

On-Line Play: There is much more likely to be problems with this aspect of the site. Gameplay is, after all, what Hasbro does, and they've just launched a new portal specifically dedicated to playing board games on the Internet. It is, at best, unlikely that they'll ever add ED to this stable, but it's reasonably likely that they'd issue a cease and desist if they thought they might ever want to, because that's the way these things are done. The best bet is to not have any explicit connection between the proposed site and the EDOL or the VASSAL project. Leave a link, sure, but leave the module files hosted at the VASSAL site and leave all mention of EDOL beyond the link to its existence on the Yahoo group.

Use of Star Wars trademarks: Historically Lucas's stance on this is very clear: i. all usage of his trademarked material is forbidden, ii. he's only going to go after you if you are trying to make money, porn, or both, and iii. there are a few specific instances (none of which, sadly, apply to ED) in which it's okay to appropriate them. So again, provided we're respectful, disclaim everything, and don't charge for any of this, it's unlikely that LA would come after us.

Of the two, I'd worry much more about Hasbro.

"Why can't you Jedi just do things the simple way?" - Kyle Katarn