I don't have any clue what's different from EABI and ELF
I can't draw you the big picture, since I do not see it too, but basically these are 2 different ABIs (Application Binary Interface). It matters for linking.
The EABI is the newer and commonly accepted nowdays. It's made for embedded systems, hence the "E" letter. The idea for EABI is to have an ABI that has compatibility between different compilers, so basically you can have different object files (.o) made from different compilers and still link them together... It matters for dynamic libraries too (IIRC), so you can have different libraries made by different compilers and still link (statically or dynamic) between them. Hence the plugins compiled by different compilers.
Another difference (IIRC again) is that EABI uses some kind of optimized stack space (perhaps other tricks too), so it takes less memory (and size).
One more thing, I've read somewhere that the calling mechanism for the routines is different, but I'm not sure about it. Thus I had doubts if it will work in ML, because we are calling routines from OFW, but since Alex confirmed it, I guess it's backward compatible, or it is using the old method for calling a stub. IDK. Though I may be totally wrong here. There is plenty information on the net, but I'm lazy to read it. (search for "EABI")
Basically for us it doesn't matter if we use the old ABI or the newer EABI, but since the EABI is common nowdays and it's made for Embedded systems, I would guess it's better.
p.s.
If someone has more knowledge ready to be shared and thus saving me time for reading it, please correct me or share more

EDIT:
as it seems it has better FP Emulation:
http://www.linuxfordevices.com/c/a/Linux-For-Devices-Articles/Why-ARMs-EABI-matters/