The STM32 DISCO and NUCLEO boards have dramatically altered the development landscape supplanting the use of the expensive EVAL series boards in many businesses. In conversations with ST Engineers, the uptake of EVAL boards is significantly down.
The new dynamic both in the maker space, and professional embedded space, is the ability to quickly mash-up a proof-of-concept design out of readily available parts/boards. In many cases it is a lot more efficient to order something from eBay (or equivalent market place) than to prototype something in the classic sense. I used to wire-wrap boards back in the thru-hole days, but surface mount is such a pain, and anything in the RF realm and using UFN and DFN parts needs to be built on to a real board rather than hacked together on some protoboard or with flying leads, to get any semblance of verifiable performance.
One issue I see with the DISCO and NUCLEO boards is they some times get too busy, utilizing all the pins, and in others miss useful or baseline functionality. Sometimes you want a pure break-out board, with minimum power supply and debugging connections, other times you want a MicroSD card or serial connection. Your exact needs may vary, obviously, and this plays into the wealth of boards found on eBay, and the popularity of the STM32 family of parts.
One frustration I do have is the frequent lack of basic documentation, schematics and software. This is where I see the crowd sourcing nature of the forum/community as being a place to share and distribute knowledge and experience.
If you find a new board, get a schematic from the vendor, or reverse engineer portions of interest to you, perhaps you can blog or post about it.
Below is an interesting board I'm tinkering with currently, it combines GPS and BlueTooth connectivity, mitigated through an STM32F103T8U6, and including a SWD debug interface.