I had to look twice at the 2.4.3 patch notes before I could bring myself to believe that the developers are planning on reducing the level requirement for ponying up. It makes a lot of sense, as we ramp up toward Wrath of the Lich King, it will progressively longer to reach the endgame, especially for new characters and particularly new players. The change makes sense to me, and I'm looking forward to Desolace being a less crummy place to level alts. No, you won't get a refund on previously purchased mounts, but nobody got refunds when the cost of the level 60 riding skill decreased either.
The community seems to be having primarily positive reactions to the news that basic mounts will be purchasable by characters at level 30. Ithnnin of Scarlet Crusade (posting on a level 40) feels that this change is an added insult to the game. He feels that Blizzard has spent too much energy catering to a "small new audience." He feels that the changes to make leveling easier have a negative effect on the accomplishments of those who when through the process when it was more difficult.