Lucky: I think Black cannot cut with 1 when White plays the marked stone. :)
White 1 is the strongest answer. Black 10 connects.
It seems to me that White wins.
Arno: So how about this variation:
I have not read it out completely, but if I did not oversee something early on, it looks like a complicated semeai, possibly leading to ko. But I'm sure I have overlooked something. Anyone?