User blog comment:The Milkman/Skyrim's Smorgasbord of Shortcomings/@comment-108.214.98.107-20120820205452

Since both Fallout New Vegas and Skyrim were in development around the same time period, it's not surprising that New Vegas features aren't in Skyrim (hence why Bethesda stated that Skyrim is a sequel to Oblivion and spiritual successor to Fallout 3). So Skyrim is meant to improve on those two game but not New Vegas.

Now rumors are swirling that Bethesda Game Studio is working on Fallout 4 so it's most likely that title will build on New Vegas and Skyrim.