Alejandro Valverde is a rider whose natural level (regardless of whether doped) is very high. Throughout his whole career he has amassed points from February to September being constantly in the upper echelons of results. He's about as far from superpeaker as you can get. He's a very decent TT rider, especially over shorter distances, and he is riding for a team for whom this race is of more importance than to many of the others (first home stage race of the year). He is very strong technically, good at bike handling and cornering, and has very good acceleration.
Ion Izagirre is a dynamic rider who has been regarded as arguably the most talented young rider to come out of the Basque country in the last few years. He has a cyclocross background, and thus is very strong technically and with a very good burst of acceleration.
Why are these two being up near the top of a prologue surprising, when that prologue was full of technical corners and places where that acceleration and cornering could be effective in gaining time? If anything Javier Moreno was the most suspicious Movistar rider today.
Regarding the Sky guys who made up a huge amount of the top 10, Vasil Kiryienka isn't really renowned as a prologue rider; he becomes more competitive in longer TTs. It remains to be seen if Wiggins will ever be the rider he was in 2012, and he is also known for not being the most technically adept, losing time in cornering.
And hey, it's February. Abarcá have traditionally been more of a don't ask-don't tell team, but maybe they have stepped up to a more planned preparation. It's too many assumptions to make from 7km in February. Many of the Sky guys have different goals to Valverde (how many of them want a peak in the Ardennes? How many of the Movistar guys would want to peak in the Northern Classics like Thomas or EBH?) and will be in a different place with regard to their targeting (is Porte not targeting the Giro? If so it makes sense for him to be further behind in his preparation than an Ardennes-focused Valverde, for example).
We need a few more days of racing to tell with people like these. If these were random domestiques with no results #s 12 & 35 suddenly hitting 1st & 3rd in the prologue, maybe it could be a bigger deal, but really here we're just making a bigger deal out of it than we perhaps ought to, and that's primarily 'cos it's Valverde.