I have had also a recent expereince as this, although at a different level. The speakers I had were the items that everyone believed were the "weak point", and I would refuse to get new ones because I believed I would have to spend a lot to equal them. As it turns out, I picked up some vandies really cheap, and while they sound initailly better, I don't hear differences nearly as well to the front of my system.
Point that I see here, you don't need to upgrade your speakers to get better. You can definitely get better with better speakers, of coarse, but just because a speaker is old, does not mean it is inherently going to be bettered by a new one.
There is a lot of wisdom to sean's suggestion, being that it would seem to be an improvement without changing anything. Especially if you really like your speakers. Instead of getting different, or different and better, or different and worse and better, you just get better. It's just a step up, period, no matter how much or little.
There is no reason why there should'nt be better speakers out there (there are always better speakers, amps, etc.) There is no reason you should'nt look if you want to. For me thats what this hobby is all about. I'm not a "speaker buff", but I appreciate that some people put more into thier speakers than I do. It seems to me that there are a lot of audiophiles that put a lot more attention into their speakers and amplification, and less into their front end, and make claims that the front end makes little difference compared to the gains in the speakers. From what I can see, these are the ones that usually spend the most money. I condider that audiophiles from these two different "camps" listen for different things.