With ddr4 ram out now, it's extremely doubtful that AMD will add any new processors to the am3+ line. Their most recent developments have been geared towards the APU's and a retrofit of the 8320 and 8370 fx Cpus to a 95w 'E' version that is more compatible with older chipsets like 970 and 760g. As it stands, the fx9590 is the fastest stock fx am3+ processor, but even that remains a duplicate of the 8320, an exact duplicate that happens to be factory over clocked and requires the absolute top of the line 990fx boards with over 200w capability (think there is just 5 or 6 atm) so in a nutshell, if you have an fx8320, 8350, 8370 (still just all versions of the 8320) you have maxed out potential on am3+, the only thing different with all the fx 8core is factory set speed, which can be changed with some OC and a little luck.
With ddr4, if AMD has any desire to stay in the gaming pc competition, they'll need a new platform, or any decent gaming pc will have to be Intel, no ifs, no ands, and most definitely no butts.