I think that it would be an excellent idea. The amount of times I have had to read posts 2-3 times is unbelievable. Writing things such as LMAO, ROFL, IIRC, can still be acceptable, as these are widely known and easy to read. Its jst wen ppl spk like this, makes it very hard to read.
Plus, people would learn how to type alot quicker. Which can benefit them later on.