SIG Sauer announced, last week, that they will be making their Sig P220 in 10mm. According to Modern Service Weapons, Sig will unveil it at SHOT in January.
The P220/10 will be have both SAO and DA/SA configurations, and will be available in 4.25 and 5 inch lengths. It will be based upon their all steel P220 Elite series of pistols as it is being reported.