The Mac Mini needs to be more appealing.
I would personally want to see like a semi pro mac, wipe out the mac mini. The mac pro is only so expensive because of the processors, motherboard being able to take so much ram.
If apple use a motherboard which supports one processor and half the amount of ram the mac pro has and maybe keeps or cuts the drive bays to two would be good.
Add a new nvidia graphics card which is likely anyway with maybe a ATI option too for a dedicated graphics card
and have a price tag for £600
there is a gap in the market for this, people who dont need the power and dont want a imac with a built in screen.
Just give us a tower like mac