Count Carl Icahn as among those celebrating Google’s  agreement to buy Motorola Mobility Solutions  for $12.5 billion in cash. The 63% premium means Icahn’s stake in MMI appreciated by more than $365 million since Friday’s market close, for a total of $1.07 billion. Moreover, it validates Icahn’s July agitation for MMI to explore alternatives to extract value from its patent portfolio.

In a brief statement today, Icahn said:

This is a great outcome for ALL shareholders of Motorola Mobility, especially in light of today’s markets. In the past three years we have fought long and hard to separate Motorola Mobility from Motorola Solutions, as well as bring Sanjay Jha., as co-CEO. Additionally, we have been strong proponents of the company exploring multiple ways to enhance the value of its patent portfolio. Motorola is activism at its best and we applaud management and the Board for acting so responsibly.

Icahn today also has gained more than $12 million in paper value on his position in Motorola Solutions Inc. (MSI), which has gained about a percentage point as of mid-day trading.

Overall, however, this is looking like more of a save for Icahn than a win.

According to a Bloomberg report last December, Icahn had invested around $3.42 billion in Motorola beginning in January 2007. He already had sold around $1 billion worth of shares as of the article’s publication. Motorola then split this past January, since when Icahn does not appear to have purchased or sold shares of either MMI or MSI.

Based on Google’s $40 per share acquisition price, Icahn’s MMI stake currently is valued at around $1.07 billion. His MSI position is at around $1.23 billion. If we add that to the $1 billion in earlier disposals, Icahn has realized or holds around $3.3 billion in Motorola and its successor companies. That’s just 3.5% below Icahn’s original investment — or $120 million — compared to the double-digit percentage losses he previously was facing. For example, he was down more than $700 million when Bloomberg did its math.

Again, not anything to crow about from an ROI perspective, but not close to the disaster it could have been. Particularly if MSI can return to the levels it was trading before the recent market volatility…