WSJ blogger Stephen Grocer contacted the folks at FactSet MergerMetrics to help put in perspective how long the proposed pairing has been blowing in the wind. A few samples:

349 -- The number of transactions announced involving the full acquisition of a U.S. publicly traded company in which a definitive agreement was reached since the XM/Sirius announcement.

230 -- The number of those deals that have been completed. That includes Whole Foods’s acquisition of Wild Oats, which took roughly six months and one embarrassing lawsuit by the Federal Trade Commission before it was completed.

97 -- The number of those deals still pending. That doesn’t include Google’s purchase of DoubleClick, another high-profile deal that received regulatory scrutiny. That deal is awaiting European regulatory approval, but received FTC approval in December.

Read the full rundown here.