If you have the automatic update function activated (it is by default: check under File > Options and Automatic Updates in the left-hand pane), you would have been prompted to update a few days ago (or anytime after that if you bought Studio later). This would have given you the Cumulative Update 2, or CU2. So what does that mean? All the details are here: http://kb.sdl.com/kb/?articleId=4947#tab:homeTab:crumb:7:artId:4947

but mainly it means that you can now update your Java plugin without risking problems in Studio (providing you use the 32-bit Java version). It also means “major enhancements to the new SDL Trados Studio Integration API”, which in turn means – I hope – that even more people will provide OpenExchange applications (for which we are always grateful).

One other notable improvement: “intermittent issues with legacy termbases requiring reorganization no longer occur”. Good to know.