I don't think they are going to do anything especially dark again. They have families, the band is getting along, they are probably finally starting to enjoy their career in music and financial security, and based on the last two records and respective tours I doubt you'll see a major shift in sound again.
Unlike other bands where I pine for the past, I'm quite alright with what NO are doing now. I was a fan in the 80's but I discovered just how great they were in the 90's, and thought I'd never see the band live. I've traveled twice to see them since 2001, and it's great to see them enjoying themselves -- unlike the countless bootlegs where it seems they'd rather be anywhere else. If you consider the big picture it's amazing what they've overcome to put out an album as strong as WFTSC.
My only qualm with them at this point: before this tour began Hooky said they were pulling some jems out of the catalog. What happened? The set is almost identical to the 2001 shows, and for a band with such an astounding catalog that's a shame. I'm sick of BLT, TF, and YSF. If Blue Monday is so annoying stop playing it... A Perfect Kiss, Dead Souls, or anything off of 1981-82 would leave people in utter disbelief.
God willing Hooky will get his wish: a set as Joy Division, a set as New Order. I can't imagine a place I wouldn't travel to see that.