If you earn status in a given year, it is valid for the remainder of that year and the following year. So yes, if you earned silver in 2009, it is valid through 2009 as well as through 2010, expiring in February of 2011.
If you manage to score gold by December 31, 2009, you will be gold until February of 2011.
Please clarify: You reached silver by flying 25K in January? And then you somehow got dropped to 0 and have flown an additional 37K miles this year? Meaning you've actually flown 62K+ miles in 2009? I don't think that's what you mean but that's one way I interpret it.