The source of the "5000 troops in organized groups" is an 'anonymous government source'. The source of the "they are threatening to nuke us, they claim they will nuke us if necessary" is the Ukrainian government itself, the second least trustworthy source in the region. NOT GOOD ENOUGH. NOT BY FAR.
Without question they've been transferring in armoured equipment, and I wouldn't doubt the number of 1000, and some cross border shelling is believable (something the Russians think they could get away with), but whenever actual media on the ground go looking through "newly won rebel territory", they find nothing but locals. The Ukrainians haven't captured any regular Russian forces in actual combat, just that one small unit out of position near the border weeks ago.
The funniest thing in all of this is that weeks ago when the Ukrainians were making gains, they refused to negotiate while the Russians and Rebels seemed to be willing. Now that the rebels are making gains, guess what? Ukraine wants to negotiate, the rebels not so much.
This "slashdot submission" is dangerously alarmist, and completely unacceptable. The mainstream media needs to be a LOT MORE sensible about what drivel they publish. We cannot allow ourselves to get ourselves hyped up about imaginary dangers.
It would be one hell of a crime if our vaunted "fifth estate" ... normally such a pivotal key part of democratic and free countries ... helps drag us deeper into a pile of crap because they are pursuing advertising dollars.