The 234/1 would be ideal for those times when you need the speed of an armored car (say to cut off LVT's on the way to town). Although "only" a 20mm, AP @ 280 rounds per minute is nothing to laugh at if you're in an LVT or M3.
It has thin armor and would be taken out just as easily as the M8. I vote "no" until a legit tank destoyer (M18), self propelled infantry support cannon(Sdkf 251/9), and a British tank is introduced (Cromwell). 
Well yeah, it's an armored car. No one expects it to go toe-to-toe with a tank and win (although I've seen plenty of guys do it in M8's). It's a scout vehicle, or probably what's best described as a "rapid response" vehicle in AH. The Sd.Kfz 234 (just like the M8) would have it's role in AH.
If HTC
did add the 234, it would be really cool if they enabled the ability for the radio operator to drive. Anyone know how fast this thing goes in reverse?