Presumably to keep valuable postpaid customers from churning when their contracts end, AT&T today rolled out a major revamp of its Mobile Share plans.  

Perhaps most significant is that the new plans change the monthly per-smartphone connection cost for those customers on or off contract. In the past, customers paid a monthly smartphone connection fee based on the size of the data bucket they'd purchased. The old rate for connecting a smarpthone to a 300MB plan on contract was $50, but dipped to $30 for anyone purchasing a bucket of 10GB or more.

Under its new Mobile Share Value plans, AT&T has seen fit to make the monthly smartphone connection fee for customers under contract a flat $40 for all plans, regardless of how much data they've purchased. But off-contract customers were the real beneficiaries of the new rates. They'll now pay a connection fee of $25 per smartphone.     

Minor adjustments have been made to the price of data buckets as well. Among those changes, the flat rate for AT&T's 1GB plan jumps from $40 to $45, while the 2GB plan has been raised from $50 to $55. Those hikes, however, are offset by the new changes to the monthly smartphone connection fees. 

The new plans will be available December 8. 

AT&T also said it is also adding a new option to its Next upgrade plan. Customers can now choose an 18 month upgrade option on Dec. 8. That plan will be available to consumers for up to four smartphones. The new plan will reduce monthly smartphone payments by spreading them over 26 months. CUstomers would then be eligible for an upgrade after 18 months. 

The company's current Next plan spreads device payments over the course of 20 months, allowing customers on that plan to upgrade after a year. 

AT&T was trading at around down slightly in early trading Thursday to $34.38.