"Dual core" means the "core" of the CPU is duplicated on the die. That is, all the instruction decoding, arithmetic, control, etc. logic is duplicated.
It will work better than HyperThreading (assuming that's what you mean by HT) because there's two physically separate execution paths instead of just one as with HT. (SMT, which HyperThreading implements, is overrated.)
It will scale better than two of today's processors since you will now get four cores instead of only two.
The future of Intel & AMD processors appears to be in dual-core chips.
EDIT: Some URLs with more information:
http://www.xbitlabs.com/news/cpu/dis...610151158.html
http://www.infoworld.com/article/04/...amddual_1.html
http://www.anandtech.com/news/shownews.html?i=22370
http://www.amd.com/us-en/Corporate/V...04_608,00.html
http://arstechnica.com/reviews/004/s.../schema-1.html
In particular, the trend towards dual-core has to do with the fight against power dissipation and heat vs. performance.