Only entry-level cards affected.
Rebadging previous generation cards to newer ones is not a new practice, as both Nvidia and AMD have done this in the past. A popular example by Nvidia is with their mid-range 9800GTX+ rebranded to GTS 250. Most recently AMD has done the same with their high-end mobile HD 6770M to HD 7690M XT, although rebranding in mobile GPUs is commonplace.
According to Fudzilla, Nvidia will be rebadging some of their old Fermi based entry-level cards to series 600; made popular with the new Kepler architecture of the GTX 680. Retail GT 610 will be a rebranded GT 520, the GT 620 will be a GT 430, and the GT 630 will be a GT440. The idea is that these cards will come with a new BIOS, faster clock speeds and, in the case of the GT 630, come with GDDR5 memory.
The GT 440; soon to be GT 630.
It seems that TSMC fabrication plant cannot keep up with 28nm production, and with the impending release of Intel’s Ivy Bridge and AMD’s A10 Trinity processors, the entry-level market for graphics will be extremely competitive. Under such circumstances it comes as no surprise that Nvidia is rebranding previous generation hardware to keep pace in the market.