I had an HTC Desire, in which the contacts were a bit in need of updating - Anyway I sycnhed up my new S2 and made the changes on there

If i were to turn on the wifi on my old Desire and let the contacts synch up which info will be uploaded onto the google servers/devices. The s2 one or will it think the Desire is the latest and update those to the servers and ultimately re-writing over the changes i've made on the s2