A few (probably well known) issues that could be solved already.

1) Outdated answers on often searched topics, outdated answers make SO look like a relic from the past.
   - Let curators vote to pin an answer and let curators vote to make questions subject to these votings.
2) Join forces. Splitting programming related topics seems to be a bad idea.
   - Let's have it all on the same site, implement taps for it. Most people never heard of other SE sites, besides SO. There are people loving these topics but the implementation of them is somewhat hiding what SE has to offer.
3) New quality standards for closing and opining question has to be implemented.
   - The issues and opinions of the community are well known.