The Doctor, in the old series, encountered Daleks at various points in their long history.
In the new series, the Doctor encountered only Daleks from the last stage of their existence during the time war, or new ones created since then.
The casing is just a machine, after all, so it can change quite rapidly as new technology is developed. Look how much cars have changed in 100 years, but they still mostly all have four wheels, a windscreen, steering wheel, headlights, etc.
Unless Moffat rewrites the Time War (which he's entitled to do, of course), any Daleks he encounters will be ones who escaped the time war in unusual ways and can come from any point in Dalek history.
I doubt this one will be "pure" classic Dalek. It will likely be a lot more solid and real looking, move better and have better effects attached.