Alien: I would wager that the people waiting on Alien have already put down a deposit, and are predominantly buying it because of the theme. Alien is a dream theme for many, myself included.
TNA: As someone else said, completely different game at a completely different price point. It's a stripped down game and has more akin with an early 80's SS game. The people interested in TNA are not going to be questioning their choice after a POTC reveal. Again, myself included. I put my deposit down on TNA this morning and have zero regrets.
Houdini: Not in on this one, but I do think it's a really great looking game from what I've seen so far. But, having played and owned JJP games, it won't be in the same league. JJP feels polished and while Houdini looks good, it doesn't look JJP good...but it might get there. I would say out of your 4 listed, this one is closest to being hurt by POTC...but, that also assumes people are not interested in Houdini because of theme.
Tbirds: Nah. It's not even close to being in the same league.
The main thing you're forgetting is that many people buy games on theme. I think this new POTC looks great, looks like a fun shooter, lots of polish....but I have no interest in the theme so it will never be in my lineup. Same thing with Toy Story. I'm sure I'm not the only one in that boat, so JJP is actually handing over business to those other 4 games in many cases.