I'd love to see more instances. I'm not asking SOE to cater to my duo; it's fine with me if my duo needs to be a few levels higher than most groups (after all, I don't expect the duo to handle what a group of six can). And I suppose Nest will be great exp for us all the way through 70. It's just fun to have variety.
Of course, I won't only be doing Nest. It's just that instances are absolutely perfect for my playstyle on some evenings. If I need to go afk a lot, instances are perfect with their non-respawning mobs. No worry of trains, wandering mobs, etc.
Perhaps some of these other instances will be duo'able once we're in the high-60's.