Export to RTF is a nice feature but it's missing all of the other formats as well. When exporting to the clipboard please include CF_TEXT, CF_UNICODETEXT, and CF_ENHMETAFILE (you can set more than one format at a time).
See here for converting an RTF to EML:
http://support.microsoft.com/kb/253262
Text is useful as a fall-back format when an application doesn't know how to paste what's on the clipboard. This should always exist. Unicode also, in-case someone is using foreign characters in their source.
EML is equally important as RTF and should always be exported together. Some applications like OneNote will import EML but will discard formatting from RTF files.