What a cute puppy! Congradulations on your new best friend!
Jack russells are awesome little dogs, they are one of the very few breeds in the terrier group that I like. Actually the only other one I like is the soft coated wheaten terrier.
JRT's are smart too, he'll pick up on his basic obedience and potty training relatively quickly.
That little split face is so cute! Are you familiar with the breed? They're so high energy for the most part, but thats how I like them In that breed, anyway.