From the DS160 datasheet:
Device XC6SLX16
Logic cells 14,579
Slices 2,278
Flip-flops 18,224
max dist ram (Kb) 136
DSP48s 32
18Kb BRAMs 32
Max RAM (Kb) 576
CMTs 2
Memory controller blocks 2
PCI endpoints 0
Trancievers 0
Total I/O Banks 4
Max user I/O 232
From the microblaze documentation.
It looks like it takes <1000 LUTs and <1000 Flip-flops to implement a simple MCS system. As there are 4 LUTs per slice and 8 FFs per slice the MCS will take <11% of the device...
Pretty easy to do estimations if you read the documentation. Besides Avnet sells a LX9 microboard USB stick that is for embedded development using microblaze.