Actually, in the end they ended up killing the overall bill, so nothing gets passed-- no stupid lawsuit exemption for the gun industry, but also no assault weapons ban extension and gun show loophole closing. Yup, that's right, the NRA and its allies pulled their support from the overall bill cuz they'd rather maintain the status quo than get a mixed bag. And there is no reason to think that this stalemate won't remain for pretty much the rest of the year-- the "pro-gun" crowd knows that every time they bring this up the same thing will happen, and even if Feinstein et. al. get the other stuff attached to non-gun-related legislation, the GOP would either kill that too or simply pull another conference-committee debacle to strip those amendments (DeLay has vowed not to let extending the ban even come up for a vote in the House on its own).
And of course, Bush does technically support all three things (the lawsuit limiting, the ban renewal, and closing the loophole), so theoretically I'm sure they could get everything together to press to separate these items out and get them all passed. But since that would involve both pissing off the NRA and working actively against the force of Tom DeLAy (who has shown willingness in the past to go against them-- remember when he insulted Ari Fleischer and vice versa?), they'd rather just let it slide and hope that no one notices their sheer hypocrisy.