The latest changes to mw.notification are here:
It's a step in the right direction; however, some changes would definitely improve usability, as well as consistency with other notifications that users are accustomed to . E3 implemented a notification that addresses some of the concerns below  and measured positive results, but it's better to merge these ideas into the current mw.notification, which is more comprehensive.
- Positioning flexibility. Currently, the position might be obtrusive to the reader since the notification lays over the text. Adding some flexibility would let us test out different positions to measure which is least obtrusive to the reading experience while still being noticeable.
- Affordance improvement. Clicking an entire notification to close it is not a typical pattern for notifications; usually you click the entire message if it is actionable (e.g. it leads you to another screen). The entire message should only be clickable if it's actionable, otherwise there should be a dismissal affordance/icon visible to the user (http://www.mediawiki.org/wiki/Wikimedia_Foundation_Design/Agora_Icon_Set#Existing_icons). Plenty of examples of this out there; see .
- Icon support. Icons improve the scan-ability of a notification and let you know where it's coming from, whether or not you can safely ignore it, or just give fast visual feedback to a user without forcing them to read a small message. They can be especially helpful for anyone with vision issues. Again, lots of precedents on this. See .
- Make the position of the notification configurable. The definite desired positions are North ('N'), North East ('NE'), South East ('SE') and South West ('SW'), relative to the entire viewport.
- Remove the "click entire message to close" functionality and provide a "close icon" option.
- Make the inclusion of a fixed-size icon configurable (defaults to false).