Customer funcionality:

Customer accounts
Customer address books (other shipping destinations)
Order history
Temporary (not logged on) and permanent (logged on) shopping carts
Search catalog for products or manufacturers
Product reviews by customers
E-mail notifications
Foreseen checkout procedure
Secure transactions capabilities with SSL
Number of products in each category are shown
Bestseller lists
Display what other customers have purchased (relating to the current product displayed)

Administrative Funtionality

New design for user-friendliness
Add/Edit/Remove categories, products, manufacturers, customers, and reviews
Categories-to-categories structure
Statistics for products and customers
Dynamic product attributes
Tax zones, classes, and rates
Configuration parameters in database for remote editing
Not tied together with the catalog module (admin module can be installed on another server)
Payment and shipping modules
Connection to oanda.com's currency exchange rate servers for multi-currency shops
Decide what to display (and the order) in the product listings
Backup tool