Passive headphones and IEMs have been as good as they're going to get for a long time now, yes.

There are going to be large strides forward in the next couple of years via active headphones and IEMs with built-in DSP however, the future of personal audio is wireless earphones with adaptive DSP.

There's a reason that traditional 'high-end' audio companies like Focal, Mark Levinson, Bowers & Wilkins, Sennheiser, and others, are all pushing hard into the digital market: It's the future, and traditional headphone/audio companies which don't adapt quickly enough are dead.