Wikimedia Engineering's key future-facing priority for 2011–2012 is creating a rich text editing environment, backed by a revamped, normalized, more consistent wikitext parser. Our 2011-2012 annual plan aims to "Develop Visual Editor. First opt-in user-facing production usage by December 2011, and first small wiki default deployment by June 2012."
Please see the big picture for more background and motivation.
Modernize editing to make editing more welcoming for newbies, still just as powerful for oldbies.
A new, normalized, more consistent wikitext parser.
- Parsoid: Architecture and status of current implementation effort; TODO list and how to get started
- Parsoid/HTML5 DOM with microdata: Details about the HTML DOM representation of WikiText we are producing in the parser.
- Parsoid/test cases: How we are testing the parser.
Get involved 
- Join the wikitext-l mailing list if interested in following along or getting involved; there should be posts from Trevor, Gabriel, Roan, Rob, and Inez, and we're going to need feedback and help!
- Collect test cases (example pages, known problematic pages, corpus from Wikipedia, adapted parser tests) via Future/Parser test cases
- Start to hack on your favorite task in the parser TODO list, and post to wikitext-l or ping gwicke on IRC if you'd like help / feedback.
See also 
- Potential projects - Future project ideas.