If the universe is infinite, there may be infinite of matter also.
And infinite of Roundy's...Tom Bishop's..and...Robosteve's..
Oh dear...well let's hope not!
What do you mean by "may be"? If the Universe is spatially infinite, there are an infinite number of perfect copies of the Earth, perfect copies of the solar system, perfect copies of our entire galaxy out there. Elementary probability theory.
i think the most plausible hypothesis is that the universe reaches out for an almost incomprehensible distance, likely trillions of trillions of lightyears, and starts to bend back on itself. as such, if someone could travel forever, they would eventually end up whre they started. there is no solid, definate 'end' to the universe.
however, if that is true, in the massiveness of space there is likely to be several other systems with similar formations to this one, with planets similar to earth
(no, not a fe/re post, so dont kill me. just my thoughts)