hmm... depends on you. i went through the phases with my cameras (canon ixus, then a fujifilm semi-professional before the canon 450d). i didn't want to shell out too much money unless i was completely sure that i was absolutely serious with photography.
my policy is: if you're not going to make a career out of it, settle for the semi-professional. less expensive since no need to change lenses and just activate RAW feature. but if you see yourself completely and utterly committed to photography, then buy the best equipment you can buy