One place to start might be to "mirror" some of the sprints happening in Dublin, which you can see at https://docs.google.com/a/acquia.com/spreadsheets/d/1eitbzBlGFqy1OBnx830Grix1djwcA2zaCoC-X7EOylY/edit?usp=drive_web (and even register your folks interest in sprinting remotely on the given days, just be mindful of the timezone difference :)).
Some "hot topics" I'm aware of atm are (also see http://drupal.org/core/roadmap for more):
Usability
Current priorities are at http://drupalux.org/sprint, a full list of issues is under the "Usability" tag. A lot of these just need someone with some front-end chops (CSS/JS) to push them over the finish line.
- Adding default content to the Standard installation profile, so people have somewhat of a clue what to do with Drupal after installing it: https://www.drupal.org/node/79582
- https://drupal.org/node/665790 adds a nicer styling to the admin status report page.
Media
- https://www.drupal.org/node/2786785 is the issue where we're currently discussing the scope for the Media initiative in Drupal 8. There are numerous sub-issues there related to Media, see the "D8Media" tag as well.
- The main feature we want to add to 8.3 is a Media Library, which is currently being discussed at https://www.drupal.org/node/2796001. At this point, it more needs design/UX feedback than actual patching, but hopefully soon we'll be throwing code here.
Layouts
- https://www.drupal.org/node/2795833 is a useful initiative which puts elements of Display Suite in core, allowing you to select from pre-defined layouts for entity view/form modes (think the node create/edit form + the full page/teaser view).
- https://www.drupal.org/node/2296423 adds plumbing to core that is utilized by both Display Suite and Page Manager in contrib.
API-First
https://www.drupal.org/node/2794263 tracks the major improvements we'd like to make to Drupal's REST API in Drupal 8.3 to help support decoupled applications and data import/export out of Drupal, if that's an area that appeals.
Drupal 6/7->8 Migrations
An area that's very helpful to work on is to test the Drupal 6/7 => 8 migration path, and fix bugs and/or add missing migrations. See https://www.drupal.org/node/2456259 for the main tracking issue, as well as https://www.drupal.org/node/2127611 for the developer documentation.
Porting Modules to Drupal 8
This kind of effort is always welcome, and can accommodate a variety of skill levels. https://www.drupal.org/project/issues/contrib_tracker first, which should normally have the most up-to-date status on a given module, esp. if work is currently happening on GitHub or elsewhere than Drupal.org.