The main risk of not having insurance is financial. If you cause an accident and do not have a Texas auto insurance policy, you are legally obligated to pay for the damages yourself. You could easily get stuck with a medical bill that costs as much or more than your house! Also, if you are uninsured and cause an accident, the state will suspend your driver's license. However, driving around an uninsured vehicle can take a big bite out of your wallet even if you are fortunate enough to never get in a wreck. For example, if you are pulled over and don't have ID cards or a copy of your policy handy to prove that you have insurance, you will get a ticket. Driving with out insurance carries a fine of between $175-$350 on the first offense-not exactly pocket change! On the second offense, the fine goes up to $350-$1000. Then, there are the surcharges the state tacks on to your license: $250.00/year for 3 years after the offense!
If you think you can sneak by without auto insurance, consider this: Texas will soon be rolling out an insurance verification system called TexasSure, a database that will let police instantly check to see if your vehicle is really insured or not. Eventually, the state will begin checking the database preemptively, sending out warning letters and taking other actions if a vehicle shows up in the database as being registered in Texas but without Texas insurance.