That's totally up to you. Personally, I think the new clippy iPod shuffle compliments the larger iStuffs nicely, especially the iPod proper (because there are most definitely times when you
don't want a hard disk drive in your pocket). The iPhone is flash-based, so that's not as much of a concern, but still...it
feels more fragile, I guess. Idunno. Maybe I'm just looking for excuses for owning the cutest music player ever.
Since you already have the shuffle, I would keep it, at least for a little while. If you find that you don't use it any more, then you could sell it or whatever. I don't think it'll drop in price until the holidays, so its not like you'll lose money by waiting to be sure.