When the final version of Android 4.2 rolled out to Nexus devices yesterday, Google Voice users noticed a nasty bit of incompatibility between the new software and the app. Whenever a new text message was created and a recipient added, the app would come crashing to a halt, preventing messages from being sent.
Fortunately Google's acted swiftly to address this issue, and a new version of the Google Voice app is available right now from the Google Play Store. The new version 0.4.2.66 fixes the issue, so your shiny new Nexus 4 (assuming you were able to pick one up) should be fully compatible with Google's telephony service.
You can grab the latest version of Google Voice for Android at the Play Store link above.