If we take the UK press release at face value, we can be pretty sure of at least 3 important changes:
1. Different ink set (vivid magentas)
2. Different heads
3. Different dithering engines (firmware)
Remember that in the change from 9600>9800 UC>K3 there was also a change on the magentas, the magenta shifted to red and the ink became more transparent. Wonder whether it is gone back this time.
The 3800 still has 180 nozzles per head and in the photographyblog URL I see no mention of the nozzle quantity in the three x880 models nor any claim of more speed. It wouldn't surprise me if the 360 nozzles per head is a feature for the 64"model to face the competition's iPF9000 and Z6100 speed. Whether that is enough is the question.
The 3800 already had improved dithering and I guess it is a replica of that but development goes on of course.
[a href=\"http://www.inkjetart.com/3800/index.html]http://www.inkjetart.com/3800/index.html[/url] shows the difference between the 3800 and 4800 dithering. Shifting the use of the droplet range to the smaller droplets and so it is closer to the way the HP's and Canon's lay down ink.
I doubt it is the 4880 we see there. But a twin cart like the old 5000 is possible too. In that case if there's a black ink switch mechanism you can be certain that half the MK ink can be thrown away after the PK side if empty. Unlikely that Epson will spit in the customer's face again so better forget that suggestion.
I see something about improved paper cutting sequence. Doesn't sound like a rotary cutter (hardware improvement) but more like a straight cut from left to right. The rotary cutters of the competition do their work up to the 300 grams paper and last longer than what we have been used to on Epsons.
Then the prices: the pound is now 2$ but US prices will be lower. Quoted price without VAT is like today's UK Z3100 streetprice without VAT. The Canon 44" is cheaper.
The German information is 99% like Photographyblog with one exception I see 8 cartridges mentioned on the German page and 9 on the Photographyblog. Whether that means on the printer itself and then no black ink switch ? I start to wonder whether not only the magenta is back to the 9600 hue but the total inkset is like the 4000 on all machines, dropping the extra grey ink of the K3 range. I know some happy 4000 users so why not. ? Many UC users expected that solution before the 9800 etc appeared.