If you wait for the Ivy Bridge Mac mini, you get USB3 and FW800 (likely) and the device supports with high probability 2 x 2.5" drives, which means that you can have 2 TB internal storage space.
My Ivy Bridge Mac mini basic configuration would look like this:
1. Highest processor which is available (i cannot upgrade this in the future).
2. Lowest amount of RAM, Lowest amount of internal storage space. I can, and will upgrade these later.
3. Mac-compatible 16 GB RAM (look in your handbook, to check the type).
4. 2 x Western Digital 1 TB Scorpio Blue 9.5 mm WD10JPVT (RAID or non-RAID)
5. 2 x Western Digital 3 TB Caviar Green 3.5" WD30EZRX within two InXtron SK-3500 Super-S3 SK3-SBU3OS (one HDD for Time Machine, one HDD for temporary files). Silent and fast enough (USB3, FW800, eSATA). The external enclosures support "only" SATA-II so use
the correct jumper settings (click), before you install the HDD.
Another important hint is this:
https://forums.macrumors.com/threads/1210567/
I hope they redesign the cooling system in the 2012 Mac mini. The highest available processor (usually Core i7 something) can beat some of the 2010 Mac Pros, IIRC, and Ivy Bridge should increase this advantage. The HD 4000 IGP is able to decode two 4K resolution H.264 videos in realtime and supports OpenCL. This IGP supports also realtime H.264 encoding via Quick Sync. Apple uses this hardware unit in Mountain Lion to implement AirPlay.
Btw, i can see why people need SSDs in MBPs, but i think they are not necessary in desktop computers.