REQUIREMENTS: MultiMarkdown, Evernote. This script accepts text from the clipboard in (Multi)Markdown format and passes it to Evernote as HTML. The script also accepts 3 lines of metadata: Title, Notebook, and Keywords.

Markdown2Evernote

property markdownloc : "/usr/local/bin/multimarkdown"
property tid : AppleScript's text item delimiters

set mdSource to the clipboard

--check for Title metadata
try
	if text item 1 of paragraph 1 of mdSource = "#" then
		if not text item 2 of paragraph 1 of mdSource = "#" then
			set theTitle to text items 3 thru -1 of paragraph 1 of mdSource as string
			set theTitle to my trimEnd(theTitle)
			set mdSource to my RemoveFromString(mdSource, paragraph 1 of mdSource)
		else
			set theTitle to my date_format()
			set mdSource to mdSource
		end if
	else if paragraph 1 of mdSource contains "Title:" then
		set theTitle to text items 8 thru -1 of paragraph 1 of mdSource as string
		set theTitle to my trimEnd(theTitle)
		set mdSource to my RemoveFromString(mdSource, paragraph 1 of mdSource)
	end if
on error
	set theTitle to my date_format()
	set mdSource to mdSource
end try

--check of Notebook metadata
try
	if text item 1 of paragraph 2 of mdSource = "=" then
		set theNotebook to text items 3 thru -1 of paragraph 2 of mdSource as string
		set theNotebook to my trimEnd(theNotebook)
		set mdSource to my RemoveFromString(mdSource, paragraph 2 of mdSource)
	else if paragraph 2 of mdSource contains "Notebook:" then
		set theNotebook to text items 11 thru -1 of paragraph 2 of mdSource as string
		set theNotebook to my trimEnd(theNotebook)
		set mdSource to my RemoveFromString(mdSource, paragraph 2 of mdSource)
		
	else
		set theNotebook to my find_default_notebook()
		set mdSource to mdSource
	end if
on error
	set theNotebook to my find_default_notebook()
	set mdSource to mdSource
end try

--check for Tags metadata
try
	if text item 1 of paragraph 3 of mdSource = "@" then
		set theTags to text items 3 thru -1 of paragraph 3 of mdSource as string
		set theTags to my trimEnd(theTags)
		set AppleScript's text item delimiters to ", "
		set theTags to text items of theTags
		set AppleScript's text item delimiters to tid
		set mdSource to my RemoveFromString(mdSource, paragraph 3 of mdSource)
	else if paragraph 3 of mdSource contains "Keywords:" then
		set theTags to text items 11 thru -1 of paragraph 3 of mdSource as string
		set theTags to my trimEnd(theTags)
		set AppleScript's text item delimiters to ", "
		set theTags to text items of theTags
		set AppleScript's text item delimiters to tid
		set mdSource to my RemoveFromString(mdSource, paragraph 3 of mdSource)
	else
		set theTags to ""
		set mdSource to mdSource
	end if
on error
	set theTags to ""
	set mdSource to mdSource
end try

--convert (Multi)Markdown to HTML
set rawHTML to do shell script "echo " & the quoted form of mdSource & " | " & markdownloc


--create new Evernote note
tell application id "com.evernote.Evernote"
	
	if (not (notebook named theNotebook exists)) then
		make notebook with properties {name:theNotebook}
	end if
	
	set N to create note title theTitle with html rawHTML notebook theNotebook
	
	repeat with i from 1 to count of theTags
		set x to item i of theTags
		if (not (tag named x exists)) then
			set tag1 to make tag with properties {name:x}
		else
			set tag1 to tag x
		end if
		assign tag1 to N
	end repeat
end tell



(* HANDLERS *)

on trimEnd(str)
	-- HAS (http://applemods.sourceforge.net/mods/Data/String.php)
	local str, whiteSpace
	try
		set str to str as string
		set whiteSpace to {character id 10, return, space, tab}
		try
			repeat while str's last character is in whiteSpace
				set str to str's text 1 thru -2
			end repeat
			return str
		on error number -1728
			return ""
		end try
	on error eMsg number eNum
		error "Can't trimEnd: " & eMsg number eNum
	end try
end trimEnd

to date_format() -- Old_date is text, not a date.
	set {year:y, month:m, day:d} to (current date)
	tell (y * 10000 + m * 100 + d) as string to text 1 thru 4 & "." & text 5 thru 6 & "." & text 7 thru 8
end date_format

on find_default_notebook()
	tell application id "com.evernote.Evernote"
		set enNotebooks to every notebook
		set defaultNB to ""
		repeat with i from 1 to count of enNotebooks
			set theNB to item i of enNotebooks
			if theNB is default then
				set nbName to name of theNB
				set defaultNB to defaultNB & nbName
			end if
		end repeat
		return defaultNB
	end tell
end find_default_notebook

on RemoveFromString(theText, CharOrString)
	-- ljr (http://applescript.bratis-lover.net/library/string/)
	local ASTID, theText, CharOrString, lst
	set ASTID to AppleScript's text item delimiters
	try
		considering case
			if theText does not contain CharOrString then ¬
				return theText
			set AppleScript's text item delimiters to CharOrString
			set lst to theText's text items
		end considering
		set AppleScript's text item delimiters to ASTID
		return lst as text
	on error eMsg number eNum
		set AppleScript's text item delimiters to ASTID
		error "Can't RemoveFromString: " & eMsg number eNum
	end try
end RemoveFromString