I kept a vigil on eBay and picked up a whole A1200 PPC Tower set up for $900. It was a lot to lay out a couple months back, but I have since broken my A2000 setup into its component pieces and sold them on eBay. I think when everything was said and done, my upgrade cost me in the neighborhood of $400.
I have a Blizzard 603e/240Mhz w/SCSI and 256M RAM. The RAM was my main reason for it. I had a GVP 040/33 Combo A2000. I was very happy with it, but to upgrade it from 16M to 64M was going to run me roughly $100/16M SIMM or $400. I never have RAM issues now and do not regret my choice.
I will get an A1 and OS4 when it comes out, but if it takes months more to materialize.. it won't bother me.
With this setup I can play very large 100+meg MPEG video files with sound surf the web, my amiga is connected to a cable modem.. life is good.
Bottom line: it would be better for you to wait for an A1 (if you can afford to get one), but when will it ever arrive? I waited years and years. Rumors said new systems.. then nothing.. new systems.. and nothing. I am most happy with my decision.. and I only bought this system 10 months ago.