The TI-92 in addition has symbolic manipulation features, interactive geometry, a text editor, and 3D graphing, a statistics editor, matrix editor, and a function evaluation table. I don't think it has condition numbers, though. I don't know about the solver, though. But if you're really serious about getting something done with math, you should use a computer program, like Mathematica. It offers at a lot more functionality and ease of use than a calculator can hope to.
Calculators are useful primarily as teaching tools because they can be taken to the classroom.
It would be nice if Mathematica came at the price and portability of an 89 or HP 49. I have an absolutely ancient version that I got for free that can do 15 times as much as a handheld calculator. Oh, and if you're going to ISO this weekend, I'll be the one wearing a giant blue red and yellow propeller beanie. With a llama on the top. I would not like to see more articles on the raw math, but on it's applications.