No, actually not. All Adobe software is single use by a single user, whether installed on one or two systems, and including for the 32-bit CS4 components included with some CS5.5 suites
Yes, that could be the answer ... but in all other aspects, this package is treated as TWO separate products -- I have it listed as two products at my Adobe product page, I've got two separate registration "rewards". And I remember a couple of months ago it was mentioned in the Premier Pro or After Effects forum by one of the heavy contributors (I haven't been able to find it again, though). That's why I'd like an "official" answer (I'm in no doubt, that i is possible and it will work, but I'm curious if it follows the rules)
It's all part of the same purchase for a single user under the same EULA... It's just listed separately because it's two different generations of products included for convenience, but it's bundled together from a licensing and usage standpoint.
Feel free to get official confirmation from Adobe on this if you like or feel it necessary.