After spending an extended amount of time with the metro aspect of Win8, here are some impressions:
1. Apart from tweetro and gleek, there are barely any functional twitter apps. It is baffling that rowi only loads the 100 recent tweets and there seems to be no way to load more. Metrotwit crashes at a drop of a hat, hopefully this will be fixed in the future. The paltry selection is pretty surprising to me, I expected more social apps.
2. There are a plethora of apps for reddit, and most of them are above average. Reddit to go! and ribbit are the best ones aesthetically and functionally but ribbit crashes a lot. /r/etro and reddhub are also fine. Reddimage is worth a special mention. It displays image posts in a highly convenient manner, and it looks beautiful and the app has been very stable for me.
3. Slapdash is more than good enough for my podcast needs. The xbox music app is awesome as well, It has replaced spotify for me. I had zune pass last month so I have experienced xbox music both with subscription and without and it is good enough for my needs in the free state. The design and functionality of the app are quite lacking though, hope they add more features from the zune app such as podcast management, etc.
4. For ebook reader apps, the Nook app is the best looking, but i'm not too interested in the nook marketplace. The kindle app is pretty barebones and "app storage limit exceeded" errors in it. Cant really see myself using my laptop for reading, so probably wouldnt use these apps anyway. Audiobooks8 is pretty awesome though. It has the entire librivox catalogue in a easy to maneuver interface.
5. There aren't many youtube apps either. Primetube is the only good client on the store imo.
Initially I thought I wouldn't be using the metro side of things too often, but I find myself relying on it for many things which are more convenient to do than on the desktop side of things.