If there's one thing I hate, it's plugin problems. That's plug-ins as in browser plugins, or one of the few reasons why I switched from Mozilla Firefox to Google Chrome for my default browser. In Chrome, a crashing plugin only affects itself; the rest of the browser is spared the messy issues (and random shutdown) that arise from problems on a page. The worst that can happen is that the actual tab your own shuts down: the rest of your browsing experience should remain unaffected by a plugin catastrophe.
Well, Firefox is borrowing a page from Google's book of process isolation, for that's the exact technique that Mozilla has built into the Lorentz version of its popular browser. The various tabs you open in Firefox Lorentz remain isolated from each other's wicked ways, in that crashing plugins will only affect the page or tab they're on--prompting a gray fade-out of your screen and an automatic reload, if you so choose. The rest of your multi-tab browser will stay exactly the same as it was pre-crash.
Neat, huh?