All I'm saying is that if someone wants to shut it down, they will. MAME is not 100% clean. Their website alone is filled with enough infringements to cause some trouble. Plus, if some company that owns the rights to a game supported in MAME started threatening lawsuits, how much money does the MAME project have saved up for lawyer's fees?
I don't really think the MAME team has to worry about being sued anytime soon. You need to remember that MAME is not exactly a household word, and while we enjoy that wonderful program, most of the mainstream world has no idea what we're talking about.
(I of course make this assumption based on my friends and acquaintances, most of whom don't know 'what a Mame is')
Remember, calling in the lawyers is expensive, so I don't think game companies are going to go that route unless absolutely necessary.
Now, if I may compare Apples to Oranges: the music industry had to* really go to extremes (suing their own customers) because (according to them) they were losing money. Now videogames are booming. They've gone from a hobby for adolescent boys to a multi-billion dollar entertainment industry. None of these companies are going to start a war with MAME over decades old games that a large, dedicated (but still an overall minority) group enjoy.
(* whether the RIAA really
had to sue their customers is open to debate for another thread on another board).
Also keep in mind, as Peale said, that emulators are legal. You can say "oh but they mention Pac-Man" all you want, but it's legal, plain and simple. Colecovisions Expanision Module* (that played Atari 2600 carts) was also legal (after court battles) and they used the word Atari pretty prominently (as far as I know, but who would buy a product without knowing what it does).
(* perhaps the wrong example but you get the gist)
Long story short, MAME is pretty much safe. Don't sweat it.
That's just my pair of tokens. History has proven wrong before and may do so again.