Performance wise the card should be around the Geforce GTX 780 and it should cost a bit less than the $499 that Nvidia wants for the card with the recent price drop. We have heard people mention $449 as a price and it is interesting to notice that for $499 Nvidia gives out three games and a $100 discount on Shield, while in AMD case you only get the card, although you get a brand new card.
It looks like tables have quickly turned as the Radeon R9 290X is selling like no card in recent history, but Nvidia has put a lot of pressure on AMD sales with the recent price drop. We are sure that AMD fans will also go for Radeon R9 290 as some early benchmarks are showing that in a few games at higher resolutions this card can beat the Geforce GTX 780.
It will need more power than a 780 and with power comes more heat, but also higher frame rates.