Are there many applications out there that are multithreaded to make duel+ processors useful? I've heard that with duel processors single processes are actually much slower than on a faster single cpu due to those small fractions of a second lost when the two processors communicate with eachother but of course are much faster when multiple cpu cycle crunching processes or multithreaded applications are running. I guess my question is, are duel+ processors of much use this point in time and do you think multi-threaded software has a future?

Well first of all, a thread does not need to be ran on multiple processes and actually just act as another processes. Secondly, most programs that have multiple threads have more than 2 or 4 but have like 15+ since it allows a program to do work in parallel on a non parallel machine. Therefore, all the extra processors do is distribute those threads evenly so each one has less work to do. That is why it improves time on threaded programs.

As for sinlge thread programs running slower on multicore machines has to do with the how the multicores are implemented. Since many of hte multicore machines have cores that are quicker by themselves than the current single core processors, it should not affect the time.

Not all programs utilize both processors, as this is a somewhat new technology. Some programs use multiple "threads". Windows gives programs threads, which is basically processing time. Multiple thread means the program can be doing multiple things "at once", even thought in reality the processor processes one thing at a time, unless you have more than one.