Ask questions like this and you will always be told (something like) 'something better is always just around the corner' and I would tend to agree. Technology is essentially obsolete almost as soon as you buy it (slight exaggeration but you get what I mean). If you see something you want, that will do what you want, buy it and don't look back.
However with a company like Apple that don't release new products every other month and stick to a fairly strict release cycle sometimes it does pay to wait a month or two for their latest and greatest to come out.