What (if any) is the significance of these results?
Not much significance. Tusk and Kaczynski being trusted by 32% of voters probably reflects the real strength of the respective parties right now, Sikorski is the obvious candidate as successor to Tusk (particularly with his good connections in the UK and others built up as Foreign Minister, as well as his former association with PiS) and Komorowski has done a very good job as President.
What's interesting is that Miller came out so high, well ahead of any other PiS candidate. It should be a clear sign to PiS that they desperately need to develop other members of their party - not idiots like Hoffman who irritate voters, but rather people that voters regard as credible.