"I predict that there will be a glut of cordless tools on the market in a few years that need new batteries. The batteries aren't cheap either."
???If this were true there would already be a glut. I bought my first cordless drill in 1981. I have owned 8 since, 4 of which are still running. There is little market for tools with dead batteries when you can just buy a new one for a little more than the cost of two batteries. It is a shame that most end up in the dump because we choose to buy another tool instead of new batteries, so guess the glut will be in the dump. I have been buying new batteries for the last four years and the tools are still going strong. I do lust over the new technology though.
I use my 18 volt Dewalt circular saw a lot more than my corded saw in my home repair business.