Portable Media Centers are perfect for travelers and kids – but that's about it. They, unlike audio devices, truly require the full attention of the user to make the investment worthwhile. You can get video, audio, pictures, and… and… no RSS feeds, no “offline” content, no features to backup licences or ratings, no ability to develop your own plugins to extend the hardware's functionality. If you want to spend ~$500 on a rich uber-mobile media experience, I'd push you to a Pocket PC (with CF or SD slots) before I would a PMC. Battery life definitely comes into play, as does the issue of space – but the price point of this Microsoft venture is its biggest weakness. There aren't enough people who need it today; even prosumers aren't sold on it yet. I can't see a “perfect” solution on the landscape – everybody wants something different.