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.