Well here's the info I got recently from a phone conversation with NOS4GN:
Tail light lenses: Tooling is gonna be pricey due to size of the lenses (compared to the rest on the car). There's a good supply of nice red lenses out there and most people are happy with that, so right now they can't sell enough to keep costs down vs. cost of tooling. In other words, if they did them now they would equal the approximate current market value of NOS lenses. When demand goes up in the future (and if the economy gets better) they will be reproduced, it's more a question of "when" and not "if".
Back up lenses: They have a NOS set being copied and tooled up as we speak. supply vs demand vs tooling cost is much better ratio on these and they expect them to be done and being sold by the end of this year. Gimme a HELL YEAH!!
Bezels: Same as tail lenses, crack free ones are easily painted and just not enough demand yet.