After watching a drone fly around in a cage at the ESRI conference, I decided to head upstairs to the technical workshop about creating vector tiles.  Here are a few things about them that you should know.  

• You can only create them with ArcGIS Pro 1.2 (or 1.3 when released next week)
• ArcGIS vector tiles use the Mapbox vector tile spec
• Styling is stored in a json file
• They use more aggressive overzooming, built on their generalization routines, so they don’t have to generate as many tiles
• If you want rotated text in your custom apps, you will need to use Javascript API 4.0
• Currently ArcGIS Pro 1.2 cannot display vector tiles.  You have to wait for version 1.3 to view vector tiles in ArcGIS Pro.
• There are some vector tile editors on Github to help you with changing the styling json and view it at the same time.  Here is one.
• You can publish vector tile layers to ArcGIS Online right now, or to your Server/Portal at 10.4+
• If you plan on replacing your current map services with vector tiles, you really need to redesign your map.  You should use feature layers with simple, unique value, graduated, or class break symbols.
• Limit the number of layers, try not to duplicate them like you did for rendering at different scales.  The symbolization in ArcGIS Pro will handle scale based sizing and scale dependent symbology just fine for one layer.
• Unlike ArcMap, in ArcGIS Pro 1.2 layers do not draw at their max scale by default.
• Only the web mercator aux sphere projection is supported for vector tiles right now.  That will change later.
• No plans for ArcMap supporting vector tiles.
• The print server does not support vector tiles at this time.  That will change later.