An interesting situation in desktop printers to be sure... I was surprised by the cartridge-size decisions on both the Canon Pro-300 and the two new Epsons. That said, the very short life on the initial inks with the P700 may be strictly an initial ink problem - that ink is essentially going into the hoses. A 13" printer with 25ml cartridges isn't going to have great cartridge life, but it may not be as abysmal after the first set (having to buy a set of ink with the printer is very unfortunate, though). Keith Cooper often keeps printers a while (and is on here from time to time) - if he still has the P700, it'll be interesting to see what his longer-term experience with ink consumption is.
Looking at B&H's website, the P700 makes NO sense, compared to its own P900 stablemate. The two are effectively the same price unless the P900 comes with underfilled ink cartridges (P700 is $800 plus an immediate set of spare inks for $379). The P900 is $1200, but comes with inks that are twice as large - it effectively comes with that first set of spare inks. Each ink for the P700 is $37.99, while the P900 inks are $41.99 for twice as much ink! The P900 should leave some ink after setup (again, assuming the initial cartridges are full), because the longer hoses will only take a few ml more to fill, while the cartridges have an extra 25ml. Unfortunately, they use the same maintenance cartridge (fortunately, it's cheap) - that's going to fill even faster on the P900, because it has slightly longer hoses.
I was very surprised to see those tiny inks in Canon's Pro-300. I thought we'd left low-end desktop cartridges in high-end photo printers behind a while ago. it's not the same ink inside, but it's a very similar cartridge to what's in Canon's $100 printers, and it just doesn't hold enough ink for a $800 13" printer.
The Pro-1000 is an older printer, but it uses a top-end modern inkset. It's identical to what's in Canon's current big roll printers, and it actually uses the same head as well. The ink cost per ml is about 25% higher than for the big roll machines ($700 for a set of 80 ml cartridges, while 160ml carts for the roll printers are $1150 per set, for twice the ink). Will Canon release a "Pro-1200" soon? If so, will it be similar to what they did to the Pro-2000, 4000, 6000 lineup last year when they introduced the Pro-x100 versions (user interface and paper handling improvements, but same inks, heads and print engine)? Or will we see some of the ink improvements from the Pro-300 migrate into a full 12-color inkset?
The only other high-end desktop printer out there is Epson's P5000, and it's big enough that if you have space for it, you can probably fit a 24" printer. Depending on rebates, it also may not be much cheaper...