it is beta version. i am in beta program. i just want to give happy news related this topic i don't know ETA. i know it is very annoying that we cannot debug on Mavericks but you wouldn't want to work with beta for your production developments. i still use 4.2 and 4.3 beta. i test my project on both versions. i suggest you to use windows version on a virtual machine for debugging, i debug like that. as all beta products you will have another problems if you use beta. as you watch on unite 2013 videos there will be many good features especially for 2D. we should be patient for this features until they are ready.