Where have you heard this from? No offence but it sounds sort of a hippy-like theory which has used science words to sound plausable.
We currently exist in a 4 dimensional (at least on a large scale 4d) universe, as Farscape says, 3D space and 1D time. We already have lower dimensions, 1D and 2D space existing within our universe (smaller dimensional spaces can be embedded within larger dimensional spaces).
Its not thought that 2D universes (and especially 1D) with life can exist. A 1d lifeform would be confined to a line. Objects would be unable to pass one another, so you can never go from a setup like ABC to ACB, because B cannot move out of C's way to let it past. Hence you can't get much complexity.
A 2D space doesn't have this problem, you're on a plane, but now you generate other problems. Consider our digestive system (or even worse, our circulatory system). Its a long "tube" though us. Thats okay, because its enclosed within our bodies. What about a long tube through a 2D object, it would split the object in half. Hence you can't get objects with overly complicated makeups because they'd fall apart. Not to mention the whole problem about disipation of radiation in only 2D being too "slow".
1D and 2D life forms in our own 3 spacial dimension universe wouldn't happen because it would require things to be confined to 1 or 2d, which doesn't happen.
Of course, if you believe in the whole "ascension, higher planes, conciousness as energy" palarva, then I doubt any of that would bother you. Suffice to say, at the moment, our understanding of physics says "Forget it" when it comes to life anything like our own or even a universe stable enough for life to appear for 1 or 2d universes, hence I don't see how there is a current line of thought that is anything more than philisophical mumbo jumbo which is pointing towards "a large scale evolution in or around 2012 to the 4th dimension" I'm afraid

Nor does anything point to "ascension" in 2012 or any other time.