Conversion is generally a positive. The dilution was assumed beforehand by most analysts, so all that wakes anyone up is the reduction in balance sheet debt. Short interest hedging the convertible disappears, which tends to encourage people.
To the extent that the shares were less-than-fully hedged, they appear in accounts that tend to be more fixed-income than equity oriented, so volatility may increase for a very short time as they are redistributed or hedged.
But I'm the long-horizon fundamentalist. This is not, in itself, a material event. Its major long-term impact is to make debt issuance easier down the road.