Well Russian sailors were there to collect the first before this even happened. So hardly surprising your country delivered it
Whether they will get the others is another matter.
To justify a cancel of the sale, Obama must give more reliable proof of Russian involvment in the conflict. If you do not consider the Crimea annexion, of course.
I'd like to mention a point : next 18 september 2014, Scotland will decide if they remain in the UK or become an independant country . That sounds really unbelievebale, because i'm sure that if they choose independance it will be done peacefully. And it was the same for most ex-USSR countries.
So, yes, it's possible to declare an independance peacefully after a referendum. But, obviously, not in Ukraine. Why ?
Dave will probably disagree, but IMO, it's simply because this gvt is led by nationalists and extremists.
If a part of your population wants to leave, just let them go, don't kill them. It's a nonsense in Europa in 2014.