Plain text from editors will now be interpreted as an SVG document when pasted into Inkscape (and not currently editing a text object), so you can now open an SVG file in your text editor and copy and paste the whole file into Inkscape (Commit #14f53899, Known issues). This only works with complete SVG files, not with parts. This was originally a bug fix for copy-pasting SVG data from applications that do not use the correct mime type when copying their vector contents to the clipboard, but appears to have other potential uses, too.