Mariupol Control

Q34: By the end of 2015, who will control Mariupol?
Ukraine: 85%
Donetsk Rebels or Russia: 13%
Someone else: 2%
(Definition note: Control in this question refers to de-facto physical control, not legal control.  If Mariupol is in control of officially recognized Russian forces, this question will resolve as "Rebels or Russia".  Mariupol in this question refers to the city centre.  "Someone else" covers contingencies such as UN control)

The Ukrainian city of Mariupol was recently shelled by rebel forces.  It is currently controlled by Ukrainian forces, although it is close to rebel-controlled areas.  There has been some speculation that it might be attacked by the rebels in an attempt to create a land bridge between Russia and Crimea.

I think that Mariupol will stay in Ukrainian hands.  Capturing it would be very difficult; according to the source above, it would " involve urban warfare on a scale unprecedented in the conflict".  Also, it is unlikely to be ceded by Ukraine in any sort of diplomatic solution.