Pros:
DHTML nav is intuitive and saves time with subcategories. Their old menu was just getting too full. Also, looks better on my Pocket PC, since there is no side nav.
Cons:
They did away with the domain search at the top of each page. This is very useful for someone like myself who is always searching for domains. Also, they still haven't added "Access Commission Account" to reseller menu -- this would be helpful since I am constantly withdrawing money to buy/renew my domains. Finally, the color scheme is nice, but the light colors make everything blend together. The previous high-contrast layout was more utilitarian.