Just a note, guys...the "40%" increase on the chart is the increase from Carrizo to "Zen". Carrizo is the Excavator chip, which is coming out this year, so the 40% is on top of the improvement between Bulldozer & Excavator. So, the FX-81xx series was "Bulldozer", the FX-83xx series were "Piledriver", & there were never FX-series chips under "Steamroller" or "Excavator", making it slightly hard to make comparisons. But the Steamroller APUs (Kaveris) had, what, a 5-10% increase in performance over the Piledriver (Richland) APUs? Assuming Excavator/Carrizo APUs get a similar 5-10% improvement, that could be extrapolated to a potential increase of anywhere from 55% (low-end) to 70% (high-end) going from a Piledriver FX to a Zen FX.
Does that potentially put them behind in performance compared to Intel? Don't know, depends on whether Intel has said what kind of performance improvement Skylake will bring over Haswell. But even if Skylake brings a 10-20% increase in performance for Intel chips, that still narrows the gap (i.e. if Haswell has 60% better performance than a Piledriver FX, Skylake would be 75-90% better, dropping the gap significantly).
But, this is all just speculation until we can get some actual benchmarks.
EDIT: fixed that BB code...