I don't like needing to create and maintain two separate NuGet package sources lists: one for Visual Studio and the other for LinqPad - can't LinqPad use VS's list?
It would be a lot of work. Keep in mind that if that were the case, modifying the NuGet sources via LINQPad's UI would also affect Visual Studio. This would have to happen such that there was a 0% chance of breaking Visual Studio. Also, LINQPad has a different authentication mechanism for package feeds: it lets you specify a username and password with each source; VS prompts for and caches credentials on demand. The first step would be to figure out how to play in with VS's credential cache and that itself is likely to be nontrivial.
Yeah, excellent points.
Though something like a one-way "Import NuGet sources from Visual Studio" button would still be handy, but yeah, probably not worth the effort.