Sprint just released a blog post that their LG Viper LTE will get the Ice Cream Sandwich rollout starting today. They also shared the usual disclaimer that it will be rolling out in batches, so if you don't see it today, just give it a few days. Here's a quote with the details,

11/1 - LG Viper 4G LTE Software Update - Android 4.0 (Ice Cream Sandwich) - LS840ZVI
LG Viper 4G LTE Software Update - LS840ZVI

- Number of users displayed on Hotspot
- Upgrade of the Google OS to Ice Cream Sandwich (Android 4.0)
- Improved Lock Screen
- Home screen folders
- Improved Android Browser
- Improved Camera Experience
- Face Unlock
- Resizable widgets

Important Notes:
- Software version is LS840ZVI
- Updates may be released in stages. When checking for the update, you may receive a message
that no update is available, check back later or wait until the update notification is sent to your device.
- Refer to the LG Viper 4G LTE Software Updates blog for install instructions.
If you are one of the lucky ones who have already received this update, sound off in the thread and share your experience with those of us who still have to wait!

Source: Sprint