Ok I have to admit the information in this post is not exactly piping hot right out from the oven, but for anyone who happens to be deciding between a Samsung i450 and Nokia N81 this may be helpful.
They're in fact very similar so it's largely up to design and brand preferences, and whether your choice of being connected is high speed 3G (which only makes sense if you've got a data price plan) or you don't mind getting connected only when there's a hotspot.

The i450 is touted as a music phone with input from Bang & Olufsen's technology while the N81 is more of a well rounded entertainment phone with greater gaming possibilities. Plug in your own headphones and the N81 will definitely not disappoint though. Plus the fact that I'm a cheapo, WIFI capabilities was definitely an attraction for me cos I can go online at (free!) hotspots. So between these 2, I'd say buy the N81, which I did. But be mindful that both phones have pretty sucky cameras.

I'm pleased to say that the N81 is the precursor for later N-series models as far as design is concerned. Below are the N78 and N96, which should be out on the market very soon.