LX3 to DSLR

I have an LX3 which I enjoy using very much.

I am now thinking I would like to move up to a DSLR (keeping my LX3) for greater flexibility (although it might be a while before I can afford another lens), and improved IQ. I am also considering the Panasonic G1. The main DSLR I have considered is the Pentax K-x.

My question is would I notice much of a difference from my LX3 with the cameras mentioned (with the kit lens) or would I be wasting my money in my pursuit of better IQ.

Thanks in advance.