President George Bush went to Ukraine in 1991 (shortly before the USSR breakup) and urged the Ukrainians not to secede from the USSR. He was probably thinking there would be a lot of instability if/when the USSR broke up.

I was surprised by the breakup (which seemed a tactical ploy by Russian president Yeltsyn to overthrow Soviet President Gorbachev) but not surprised that it was peaceful.

In an era of bipolarity, there were two superpowers as you know, the Union of Soviet Socialist Republic (USSR) and the United States of America. The two powers were so great, it seemed virtually impossible that the Soviets or the Americans will be forced to yield to each other. However, with the discovery of the nuclear weapons, the arms race began and therefore, secured peace in way. Mutual assured destruction (MAD), ironically became the way the global superpowers kept each other at bay without a significant security dilemma issue. According to George Kennan who wrote the Sources of the Soviet Conduct, he argued that the Soviets believed themselves to be in a perpetual war with capitalism and the fact that Soviet's expansionist tactic was actually not part of the Marxist ideals. The Soviets were expansionist for defensive reasons as well as path dependent reasons. ( Tsarist regime, Stalin regime: authoritarian nationalism) Therefore, Mr.X did not predict that the Soviets will remain in a peaceful coexistence with the Capitalist world. So the the United States and her allies went with containment, in order to contain the Soviets. This is partially the reason why there were proxy wars to prevent Soviet expansion. See how great of a conflict the US and the USSR was in? They were both powerful according to structured realist views. Therefore, thinking like pre Cold War Europe, many people expected an all out war between the US and the Soviets, i.e nuclear war. But, the Soviet's economic power and, many many many other reasons that i will not go into unless you want an answer to that, the containment policy worked. So therefore, yes it came as a nice surprise, but not that surprising.

TL:DR Kennan was right, it just came sooner than an all out war.

EDIT: Kennan predicted that Soviet's attempt at Marxism was ultimately, economically devastating in the long run. Basically, run out the clock and the US policies will work in the long run.

Sources The Sources of Soviet Conduct.” Foreign Affairs 25, no. 4 (1947): 566–582. http://www.trumanlibrary.org/whistlestop/study_collections/coldwar/documents/pdf/6-6.pdf