Difficult choice, but I think faster CPU and more memory would allow B4 to be a real server replacement when running web applications, web server, PHP etc.
The most important feature of the B2 and B3 for me has been that its power consumption is low and that it's passively cooled. Any improvement would be good, as long as those features are not compromised.
I´d say that faster CPU and less power consumption are straight opposites. While I sometimes wish that the B3 could be faster (e.g. after uploading new images to my ImageMagick dependant photo-site) I do value the low power consumption most. As far as the list goes the bootable flash disk option seems more like a proposed solution to accomplish even less power consumption and I therefore don't think it should be a separate wishlist item. Also, I don't get the LED display option; LCD is clearly more power optimized and would allow for better resolution (read: enable displaying non-ASCII output). If any, more memory would be highest on my list, followed by USB3.
Would not an extra core or two be good. Normal there are several different services running at the same time which should be able to use some extra cores. Extra cores does not take that much in power consumption.
Would like a decent file transfer rate. like 60mb/s minimum. Also two disk bays would be nice. flash boot card/disk is a good idea. led display is useless for me.
The main argument for buying my first B3 last week, is the fact, that there are no fans needed.
Developing a new B4 will have more memory and a faster CPU. Moore's law comes into my mind. More memory means, that additional services can be run (faster).
But as long as no fans will be introduced, the only wish I have, after some first playing with the B3 is the introduction of enterprise disks, which can run 24 hours a day. (I've got a wd20ears-00m installed.) Including a extension of the manufacture-warranty to at least 3 years.
I hope not. One big plus with Excito servers are the form factor, I don't want them bigger. eSata is a very good thing for those in need of more disks.
True, but a B4-XL with two bays as a separate option is something i'd prefer to a RAID1 that carries over an eSata cable. Just look at all the threads that deal with RAIDs failing because of this!
With the priority to have a simple, safe (raid) and low power solution I suggest an excito model with 2 internal bays for 2.5" HD. Actually the model B3 should have the space for such small HDs. This would be a B4 2slim As an "open" device the user should be able to add the HD's by himself.
The booting and firmware running from a SSD or a fast-flash would indeed be a nice to have too.