Here's a long and complicated page about it:

http://www.smart.net/~mmontes/ec-cal.html

I haven't actually read it yet (I'm about to), just wanted to post it now in case you're online.

EDIT: Looks like you're right on - there is a standardized date for the equinox and range of dates for the full moon in question, and I like the reasoning given - that full moons may occur on different dates in different parts of the world, making Easter at different times in different parts of the world - so this does standardize it, as you mentioned:

Easter is the Sunday after the Paschal Full Moon. The Paschal Full Moon may occur from March 21 through April 18, inclusive. Thus the date of Easter is from March 22 through April 25, inclusive. The date of the Paschal full moon is determined from tables, and it may differ from the date of the the actual full moon by up to two days. This definition, along with tables, etc. may be found in "The Explanatory Supplement to the Astronomical Ephemeris and American Ephemeris
and Nautical Almanac". This definition that uses tables instead of actual observations of the full moon is useful and necessary since the the full moon may occur on different (local, not UT) dates depending where you are in the world. If the date of Easter was based on local observations, then it would be possible for different parts of the world to celebrate Easter on different dates in the same year.

I feel better, now that the question is answered.