BTW, releasing a Mini PS3 that looks different enough could help Sony to avoid having to release PS4 too early.
Moreover, Sony was prudent enough cutting price in August 2011, so that if it has to cut again in Q4 2012 it will be more than one year later, but a Mini could help even further, totally avoiding any risk of making the cut look rushed.
Finally, Europe, Sony's main market, is in deep troubles and people have less money available, so Sony can be more sure than before that a consistent part of PS3 sales will happen when it will be priced 200 Euros or less, so hitting that price simultaneously with Mini's release will grant enough sales to justify the initial cost of shrinking with the successive savings.
Not to mention the benefits on sales in Japan.
