I consider myself a relatively advanced amateur photographer who has never strayed from advaned "point and shoot" cameras. I've become a big fan of super-zoom cameras, largely because of the composition flexibility having the zoom lens provides. (I am currently using an Olympus SP-570 UZ). I have a really good "eye" and take excellent photos. My primary subjects are nature/landscape, architecture, macro subjects, and my dogs.
I am considering getting a DSLR. I've done a good bit of reading about the advantages of SLR cameras and think I have a good sense of the objective differences/benefits between SLR and Point-N-Shoot cameras.
The primary reasons I am considering getting a DSLR:
 Would like to be able to do more with low-light conditions (less noise at higher ISOs).
 General higher image quality (less barrel/pincushion distortion, which I know is lens dependent).
 Just generally want to move the the next level of photography.
 I'm a gadget freak and want to get a new one.
My hesitations to making the switch are primarily:
 The realization that with a DSLR, one lens might not "fit all" (from macro to telephoto) so the hassle of the bulk and buying and lugging around different lenses is an issue I have to come to terms with).
 I have much to learn about apertures and shutter speeds and lenses (although this is a challenge I sort of welcome).
 Might miss "movie mode" (although I don't use it that much and I know some DSLRs are coming out with it).
For the purposes of this post, I am not concerned about the cost.
I've done a bit of research and I've preliminary decided the Canon Rebel XSI/EOS 450D seems to appeal to me (largely because of it's slightly smaller size and good low-light performance). I'm wondering if there is a good all-around lens that would, at least in the short term), provide a macro-telephoto "bridge" as I make the transition from my fixed-lens point-and-shoot.
I would welcome people's thoughts about this - not so much about my specific camera selection but about the transition from what I have to a DSLR. I guess I don't necessarily have a specific question but an interested what sorts of comments this gets.