According to recent measurements our observable universe is roughly 93 billion light years in diameter; also it appears (according to WMAP measurements) that spacetime is flat.
Supposing space is infinite.
It seems to me that it isn't outside logical possibility that there is another observable universe completely outside of our observational range and so far away it has no appreciable effect on the curvature of our universe.
Note, I'm not using the word universe here as everything in space.
As noted above in comments, I'm not competely sure I understand the question. But anyway, I'll give it a shot.
The answer is model-dependent. The standard cosmological model at the moment is the Lambda-CDM model. This model has various parameters. Depending on these parameters, the spatial curvature can be positive, negative, or zero. Observation puts (model-dependent) bounds on the spatial curvature: What is the curvature of the universe? Given these bounds, we can put (model-dependent) bounds on the size of the universe: Size of the universe . We then find that the universe is much larger than our own observable region. Therefore the (model-dependent) answer to the question (as I construe it) is yes: there are other regions of the universe in which observers would have observable regions that don't intersect our observable region (and probably never will, given the acceleration of expansion).
