The Swedish website Sweclockers.com has posted a report that could disappoint, namely that the 20 nm Maxwell-based graphics cards have been delayed.
All of the current generation graphics cards are built on the 28 nm lithography process. The report states that TSMC is not yet ready for full-scale 20 nm GPU production. According to the report, the delay is set to last until the beginning of 2015, though it doesn't rule out that we might be seeing the first 20 nm graphics cards before the end of the year.
That said, there are already graphics cards out with the Maxwell architecture – the GTX 750 and the GTX 750 Ti. These cards are still built on the 28 nm production process though, which is likely why Nvidia has branded them under the 700 series of products.
For now, this is the first instance where we've heard of this specific delay, and we haven't seen it go around much yet, so it might just be hogwash. Oh, and the report was published on March 31, so no need to point out that it might be an April Fools' joke – sorry guys.
Nvidia stuck to its policy of not commenting on rumors or unannounced products.