Yeah the first batch of -800s would need spar strengthening and other mods to support the winglets. I think its only the first 12-14. Otherwise its basically a bolt-on, and the rest of the -800s are getting them. So will the new-used 757s being delivered this year will have them also.
When you're in Ch 11, a lot of things get put on the back burner. But, with the fuel savings these offer you'd think we'd have had them already.
Other techie stuff, the -700s will have the same HGS display as the -800s, EFBs are finally getting back in the game plan again, and the 767 fleet will be getting a wide format avionics upgrade....no more round dials.
Has DL officially announced the upgrade to the IS&S flat panel display?