He's all the way there now, into the top 4 seeds, after beating the tricky Mischa Zverev on grass today at Halle.
So the top 5 seeds will be:
1. Murray
2. Djokovic
3. Federer or Nadal
4. Nadal or Federer
5. Wawrinka
The difference between the 3 and 4 seed is negligible. Still, it'd be nice for Fed to win Halle (in which case he will be the 3-seed) and have great momentum going into Wimbledon.