GlassRite Wine is a four-year initiative stared in 2006 by the UK's Waste & Resources Action Programme (WRAP), in order to "identify opportunities for the wine sector to make environmental and commercial savings." Now comes their crowning achievement, in the form of a humble CAD file:

That may not look like much, but that's kind of the point--that's a wine bottle that weighs in at just 300 grams, 188 grams lighter than the average and 40 grams lighter than its lightest antecedent.
"If adopted for all wine sold in the UK it would generate an annual glass saving of 153,000 tonnes - equivalent to the weight of more than 460 jumbo jets - and cut CO2 emissions by 119,000 tonnes," said WRAP's Nicola Jenkin. The design is available for free download on WRAP's website here.
Comments
In france and Spain there are wine co-ops where you just take any container of your own and fill it up, they charge you by the litre. Bottling is a significant proportion of the cost of a bottle of wine apparently, especially so if you buy the cheaper stuff.
I was involved in a recycling talk here in brisbane (Australia) several months ago and they presented a case study that very close to what is happening with this wine bottle design.
The case study was about using less glass in beer bottles to reduce the cost of manufacturing and logistics as well as saving materials (better for the environment). However, argument presented was in fact that this 'green' attempt actually was less green that the older, heavier bottles.
Heres why.. THe older bottles had more glass, therefore stronger, and less likely to break. Whilst this means more materials and manufacture, the bottles collected at the end had a better chance of being recycled. The thinner bottle had a much higher tendency to break- and when crushed in the lead up to recycling, a higher volume of the crushed glass obtained were too small to be recycled, and therefore disposed of. They argued that although the initial cost of the older bottles where higher and less 'green', the new bottles proved much more difficult to recycle and generated more waste (that ended up in landfill).
and if you used a wine cork you could have a greener solution than with a capsule or whatever name that has
I've had a drink bottle in the UK break on me while carrying in a bag from the grocery... This potential of lighter efficient bottles is awesome, but I hope they are careful to keep the strength needed for glass