Read this comic today:
(https://forum.twguild.org/proxy.php?request=http%3A%2F%2Fwww.gucomics.com%2Fcomics%2Fhotspots%2F2011%2Fgu_20110316.jpg&hash=b2da795a192732343c6afac36bacd5d7a4709a27) (http://www.gucomics.com/comic/?cdate=20110316)
While it is a Horde only quest chain that gives you the mount after 20 dailies, it did lead me on to a note that specified that the mount changes into the Winterspring Saber if you changed factions to Alliance. Further investigation lead to an alternate method of gaining the Saber mount apart from the current exalted rep grind:
[blizzard]In patch 4.1 we will add a new quest chain to Winterspring for the Alliance, which will be similar to the Horde quest chain found in Un'Goro Crater. This means that obtaining the Reins of the Winterspring Frostsaber for Alliance players should be somewhat similar to the way that Horde players get the Whistle of the Venomhide Ravasaur... or at least that is the idea :-)[/blizzard]
Just an FYI. =)