No, if you are not currently on an iphone then you will have to activate in store. Only people with active iphones will be able to activate at home.
This is being done to make buying iphones for unlocking / reselling more difficult.
If you are a current iphone user you will just give them the new IMEI and then your free to leave the store.
MBW, don't forget that the new data price is the same as all other 3G phones and the non-3G BB plans as well. For most people this is not a problem.
"A computer lets you make more mistakes faster than any invention in human history - with the possible exceptions of handguns and tequila." - unknown