SMS with the TouchPad is not intended to be working yet. Some of you have various behavior (works halfway, etc). However, according to HP, the Veer will get an update (as has been stated in the past events leading up to today's release) that will enable the SMS functionality.
Originally Posted by TheMarco
The Pre3 will most likely work immediately out of the box once it's released (as also stated in past media events).
Currently, only the Veer and Pre3 have been confirmed to have this type of SMS functionality once they are updated/released. There is no information (as of today) available for any of the older devices that are not the Veer or Pre3.
Hope this clears up some of the confusion.