I was waiting for a refresh in June 2013 ! I put 8GB RAM and 750 HDD into my 2009 so if there is no update I have two choices as I see it
However I would need to feel the Mini is going to be discontinued to do 2) and my priorities are an iPad Air2 to replace my iPad1 and an iPhone 6 to replace the 4S, so perhaps the real answer is nothing until early 2015.
1) 500GB SSD into my 2009
2) Buy a used 2012 onwards machine and put in RAM and SSD
2) Buy a used 2012 onwards machine and put in RAM and SSD
However I would need to feel the Mini is going to be discontinued to do 2) and my priorities are an iPad Air2 to replace my iPad1 and an iPhone 6 to replace the 4S, so perhaps the real answer is nothing until early 2015.