To the best of my knowledge, Leadtek has just become the first to officially announce a retail 9800GTX+ with their WinFast PX9800 GTX+. Promising 15% better performance than the standard 9800GTX, this card runs at 738MHz on the GPU and 2200MHz on the 512MB of GDDR3. Although it's getting on a little now, Leadtek also bundle the card with a copy of Neverwinter Nights 2.
You can find the full press release here.
Taipei, Taiwan, July 2nd, 2008-Leadtek Research Inc., a global front runner in extreme visual graphics technology development, announces the launch of the latest products in its WinFast series. The new WinFast PX9800 GTX+, represents a dazzling 15% speed boost over the PX9800 GTX. The NVIDIA GeForce 9800 GTX-based graphics card can vamp up performance like never before and provide optimal power management with HybridPower™ technology. Compatible with 3-way SLI technology, the new card gives every user the thrill of extreme HD gaming and first-rate entertainment experience.