Absolutely, though only a few at this moment.
| Shortcut | Action |
|---|---|
| ⌘ + N | Bring up the new tweet window. |
| ⌘ + Enter | Post from current new tweet window. |
| Esc, H, or Left-Arrow | Dismiss current new tweet window, or go back to previous view. |
| L, or Right-Arrow | Show the thread or author profile of currently focused tweet. |
| J, or Down-Arrow | Move down by one tweet. |
| K, or Up-Arrow | Move up by one tweet. |
| Space | Page down. |
| Shift + Space | Page up. |
If it is an essential feature (such as those already in Twitter.app), then most likely it is already somewhere on my todo list to be implemented.