A while back I decided to post a thread in the Etsy forums and get peoples opinions on this subject. Since then, I have also searched the forums for similar threads. These are some of the thoughts and pros and cons for having two shops that I pulled out.
1. Your shop is more cohesive and professional
2. Your shop, mission and message is more identifiable
1. It takes a lot of time to promote two shops
2. With two shops your customers do not get to see all of your items
1. If you have one shop with many items, be sure to use the "Sections" feature.
2. Keep in mind that Etsy does not have a feature that allows you to link shops or switch usernames without signing on and off. This can become annoying when switching back and forth between shops.
3. As long as the general look and feel of your shop works together, it is better to keep it all in one place. Find a look that doesn't make the shop look all over the place.
4. Different sections brings diverse customers to your shop.
5. Make sure the name of your shop can apply to all the items you sell.
5. COnsider what you want to be known for.
From everything I read in the forums, it doesn't seem like too many people are turned off by a variety of items in a shop as long as the sections are clearly marked. If you are thinking about opening a second shop, you may want to first try adding the items that would go in the second shop to your original shop and see how it goes. The variety might add a great touch.
As for my shop, I don't think I have enough time to run more than one although I am still considering it. In the meantime, please let us know your thoughts on this topic. Also, if you haven't already, please take a look at my shop and let me know if you think there is too much variety. Your opinion really matters to me.