Nikon DX format question?

Yes. One of Nikon's strong points is having kept the same lens mount since 1959 or thereabouts. The only other manufacturer who comes close is Pentax.

Both are here to stay, for a long time. The advantages of FX, namely a big sensor that catches lots of light and can provide very shallow depth of field cannot really be replaced with a smaller one. Also, any technological advance that applies to small sensors also can be applied to the big FX ones. Hence they automatically always stay ahead about low light performance, no matter how many improvements there are for DX sensors. "Since the FX format is better and newer." FX actually is older. DX is the newer format. I wouldn't call either one "better" - they are different. FX is more suitable for some purposes, DX for others (e.g. telephoto applications where the crop factor is helpful) DX won't be phased out anytime soon either. Unless truly groundbreaking changes occur which allow a far cheaper manufacturing of FX size sensors (unlikely to happen), the DX format will remain for consumer grade DSLRs.

As far as i know, they should. I've used a 20 year old lens on my D60 and it was fine. You will get a cropped image though, and depending on the camera body you have, you might be forced to manually focus. not a big deal.