Would this be a very good camera to buy for great quality tumblr style pictures?

Http://www.bestbuy.com/site/Nikon±+D5100+16.2-Megapixel+DSLR+Camera/2553883.p?id=1218336884671&skuId=2553883

This is the camera I'm thinking about buying, give me your opinion.

Added (1). I also want it to have long exposure.

That would be total overkill for what you need. If you like Nikon, get the D3100 instead.