AT&T’s current DataPro plan provides 2GB of 3G data for $25 per month (DataPlus offers a mere 200MB at $15 per month). Adding the ability to tether another device requires an additional $20 per month.
Engadget reports that AT&T will bump the combined maximum data usage per month for Data Pro with Mobile Hotspot service from 2GB to 4GB on February 13. Existing customers of this combined service will be notified of the increased data (no increase in price) on February 13. There is an implication that this price and service also applies to the HSPA+ 4G wireless data service AT&T is rolling out.