Well that was quick. Reported to us by Nerf2me2 are the new Nerf Stinger blasters which are the new single shot blaster in the Dart Tag range and apparently are essentially reshelled Jolts; he's picked them up from his local Toys R Us in two different packs.
The one detailed in the UK Argos catalogue is the 'Target Tag' kit which comes with a blue cased Stinger and a plastic target.
There's also a two player 'Dart Duel' pack which is similar to the 2 player Sharp Shot kit, coming with two blasters in red and green, six darts (with unique coloured tips matching the blasters), protective eyewear (with matching colour lenses) and the velcro jersey smocks.
Thanks Dustin for the heads up!