Some newly added items are not translated in 1.7.2.
I updated to 1.7.2 using the ‘Latest’ profile in the Mojang launcher. Items related to the new wood types (Acacia & Dark Oak), stained glass plus Sand and Red Sand consistently have only English labels. I’ve cross-checked Irish, Welsh, Spanish, French & German and all these have completed translations at crowdin.net. Some of these languages also have other missing translations which is presumably to do with the cut-off for 1.7.2, but seeing Sand revert to English suggests there might be something more going on here.
It’s great that translators got a notification this time around about new vocab, but it’d be useful to know about the deadline too.
Fixed as of 10 / 30 / 2013