Taking into consideration all the replies, and after some thought, I’ve decided that I intend to get a Dreadsteed.
My reasons for this are that, yes I do want a cool mount, and that it is something unique for the warlock to own and be proud of.
On reaching level 60, my initial reaction was: I want an epic mount, I’m a warlock, so I want a dreadsteed now. I think I might have been mistaken in that I believed it had to be my only epic mount. I now look at the Dreadsteed as something I can achieve, and want, before I reach level 70. If I fail in the attempt then so be it, I least I tried.
After all a sense of achievement is something most of us play for and gain pleasure from, and if the harder something is to attain equals a higher sense of achievement then I’m going to be one happy lock when I finally get my dreadsteed.