The machine which takes the place of the Horizon 7700 is the 7700 (without the Horizon). It looks just like the Horizon 7700 but it's not red. It retails for just under $2,000. The 8900 is their new top of the line machine, which does retail around $4,000 and they've also come out with an 8200 which is like the 8900 but with fewer stitches and minus a few features. I understand it will go for about $2700.
I've heard very good things from owners of the 8900; it's like the original 7700 except some of the features are slightly different and easier to use. I'm thinking of trading up, but haven't gotten a price yet.