I would be inclined to get the DSLR, but much depends on what and how you shoot. Do you work slowly and deliberately, with a tripod when possible? Or do you "shoot from the hip"? Do you want gorgeously noise-free prints, even at high ISO, or are you willing to accept a small bit of noise as trade-off for quickness and convenience? Are you willing to clean a sensor now and then, or do you not wish to "mess" with equipment maintenance?
There are a lot more relevant issues to ponder, such as whether the 8080 or the Pro1 or the A2 suit you best. Then there is the D300 (DRebel) to consider... Can you borrow any of the above to try? If not, you first have to make the SLR vs P&S decision; then I would read a few reviews, look at the samples and go for it. All of the above will give you excellent A4 prints, as (in fact) would a good 5MP digicam such as the Oly 5050/60 or the G5.