RTi is not being discontinued. It is not being replaced by LSi.
Every so often in the life of a product, we will make (small) changes, either cosmetically or technically. You benefit, because retailers will usually lower the price (not always a good indicator that change is coming, but sometimes...) and make the current product an even better value. There is absolutely nothing "wrong" with current RTi product. In fact, if I were you, I'd be leaping to grab some of these great deals on the stuff. They are great speakers (I love my RT55i's). And they are not going away.
It's dangerous for me to comment on this stuff because there's a risk that you all will think, "Well, I won't buy the current crop, I'll just wait till the next line up comes out." That could be a long wait. Product life cycles are measured in years.
If you're thinking of grabbing a great RTi deal, I'd go ahead and do it. That RT25i review made all of us here jump for joy, and that product is not going to disappear any time soon. The product is not going to change or disappear anytime soon. Relax. Enjoy.
LSi Series is a completely different line of high performance, beautifully designed and finished high-end technology speakers featuring improved driver design, an incredible ring-radiating tweeter, and super looks. We're really excited about them because they hark back to what Matt Polk originally envisioned: elite audiophile performance speakers for everyone else (you know, US).
LSi's will probably be priced a little higher, and distributed a little more exclusively, than the RTi line. But again, as the reviews have said, RTi is nothing to be ashamed of!