This is an issue which I have looked into pretty thoroughly as one of the modules on my degree was Language and Technology.
Through the research I did, I found that an amazing number of people, young and old, did NOT think that this was going to happen eventually. It came out at around 87%. The funny thing is that almost exactly the same percentage of people actually use text talk with roughly 50% admitting to using it in other situations other than just texting.
I don't think that Standard English will be eclipsed by text speak and personally I hate it when I come across it anywhere else but on my mobile! Having said that, being a huge fan of all things linguistic, I find it a fascinating new twist to our most adaptable language!
Unfortunately, I'm not sure that I wholely agree with your comment regarding schools teaching children to spell properly (check Yahoo Answers UK if you need any examples!).
If I had to pick out one feature of the English Language as my favourite, it would be its unpredictability so I guess we will just have to wait and see!