Depends on who his partner would be - but yes, based on what ive seen and what most educated analysts believe, if he played with someone like a Keith Yandle I certainly think that's a #1 pairing. If not this year, next year for sure... He has an all around game that fits with a lot of different players though.
Most "educated analysts" have almost no data to go on here, so I really doubt they've concluded that he could successfully play as a top-pairing defenseman at this stage of his career. I don't know why you think that playing with a guy like Yandle, who is known for being poor at actual defense, would make him any more fit for this role.
If you'd watched the Calder Cup finals, you'd have seen that DeKeyser had some brutal games. He's still figuring out how professional hockey functions.
I apologize I didn't really clarify what expectations I based my interpretation of Kronwall as a second pairing guy were, which was a championship winning team.
Yes, Kronwall would be a suitable #1 on more than half of the teams in the NHL - and maybe more, but I believe for us to truly be considered a cup favourite he's better suited with Ericsson on the second pairing.
His best years I noted - were the two years we played in the Stanley Cup Final, played on the second pairing... Now this isn't to compare Yandle or whoever we could find and Dekeyser to Lidstrom and Rafalski, but I believe Kronwalls defensive inefficientcies don't match up to the best forwards in the world.
If you take any prime defenseman and play him against weaker opposition, he'll perform better. That's just how things go. Kronwall and Stuart could have formed an able first pairing at that stage. Fortunately for the Wings, they had an even better first pairing in Lidstrom and Rafalski. The Red Wings were quite simply stacked on defense back then in a way that no other team was. Rarely will you ever see such an able grouping on defense, and the fact that Kronwall played on the 2nd pairing back then doesn't mean anything about his overall acumen.
I still don't see why you believe that Yandle would perform better on the top pairing than Kronwall would; if you think that Kronwall has defensive deficiencies and that Yandle would be a better fit, you clearly don't watch Yandle play very much. As mentioned, Yandle is a one-dimensional player and is not even the #1 defenseman on his own team. He is roughly Kronwall's equal in offense, and quite a bit below him in defensive acumen.