If you value first-class upgrades, at all I'd say definitely "yes." If you use your earned miles, then I'd also say yes.

As a Gold, you earn 100% mileage bonus vs. a 50% as a Silver. That's real 22500-25000 difference in bonus miles for you in 2006 if you travel 45000-50000 miles. Combine this with Continental.com Specials, this could translate to two round-trip tickets. It's about one return domestic ticket at standard award values.

More importantly, the frequency upgrades for Silvers on CO these days is somewhere between zero and immaterial IMHO. As a Gold, I feel like I have to have really, really good luck AND plan ahead to get into that precious FC.

If you don't care about either of these and/or want to make upgrades for the rest of Golds easier, then don't do it.