With the announcement of Nikon D5200, will D5100 become significantly cheaper?

I'm planning a D5100 between now and December… With the announcement of D5200 today, should I wait for the release of D5200 in December for a possible price cut on D5100, or should I buy the D5100 now?

I think you should wait for the price cut. Just need to wait a couple of months more.

If so not by much… At least for quite a while. The major camera makers don't just drop their prices because of holidays or a new model. If you want the camera buy it… There won't be enough difference that you'll notice in a year.

There might have been prices cuts already, so do some research on the original D5100 price. If there's another cut between now and Dec it won't be much since the D5100 is old-ish, I'm sure the price has already fallen from the original price, that's the way it goes with all dSLRs. Bottom line, don't expect big cuts.

Smart move going with the D5100. The only real gain worth mentioning for the D5200 is the AF sensors used in the D7000. Using that same 24 megapixel sensor was done to sell more cameras, because people think more is better. In reality, that sensor is one of the worst scoring sensors at high ISO when compared to other modern sensors.

When you dig into the DxOmark scores and find the real 'screen' number and not the print number, that 24MP sensor is weak.

The D5100 has already had a big price cut down to £405 at Amazon:
http://www.amazon.co.uk/.../letscook/
and in the UK Nikon have added £55 cashback:
http://www.nikon.co.uk/sites/cashback/default.html

So final UK price after cashback is £350, which is where the D3100 was a few months back.
I can't see it going much lower than that this year.