Oh my lord, not Samsung. No one needs a successor to the N1 that's made of ****ing plastic.
(Before you ask or point out that one of the US carrier variants aren't all plastic: the international Galaxy S is plastic all over. It's light, but incredibly displeasing to handle and a giant fingerprint magnet.)
In any case, if it's not a dual-core with a Tegra 2 chip, it's not a worthy upgrade. Samsung's Hummingbird GPU is nice, but not that nice.