I'm going with no. The parts they use for the current model will only get cheaper... Why bring out a slim this late in the generation and add to the costs of this generation when it has started to slowly wind down, or at least will by the time the super slim will release?

They already have the staff and the tools on hand.

The other option is to work on the ps4, or slim vita, or fire them. It's not like the workers doing stuff suddenly costs them money.

Maybe because console redisigns boost sales considerably.

no, at this point PS3 is selling ok, at a profit. They are focusing on Vita's launch and the run-up to a PS4 in 2013. PS3 will remain as is, for now.

Shrinking components when the chosen smaller process has been just made available can be and remain expensive for some time and a large number of units produced, but doing it choosing an already mature smaller process can start saving money very soon. If power consumption is lower enough to allow using a smaller case, raw materials, warehousing and shipping costs decrease too, and on millions or tens million units it can give quite nice economies of scale. So the conditions are three: 1) choosing a shrunk process already mature; 2) such process must offer significant economies of scale and lower power consumption compared to the current one; 3) expecting to produce the new units in a number large enough.

A final benefit: in its last years, when PS3 will cost a lot less than now, retailers will appreciate that it occupy less shelf space, a Mini model helps extending the product's life.

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.

There should be, but I don't think they will, not now at least maybe in 2014 or late in 2013

If Sony really is serious about the 10 year plan with PS3, a redesign will eventually happen to make it look new and fresh.
Will it be this year? Seeing as Wii U is releasing this year, a new look for PS3 won`t make it seem old and could steal some thunder from Nintendo which will be presenting a new product to the market.
That redesign alone would help them enough without cutting the price again - saving it for next year where it could be better for them.
Of course, all this in light of the 10 year plan!