We're not going to claim credit for this, but obviously there was quite a backlash against Sprint for using the Arrive as the poster-child for their Buyback program, at least if you go by the comments. If you recall, Sprint put the Arrive up for their Buyback program, which was prominently featured on the Sprint iPhone 4S page.
Now, perhaps due to a change of heart or perhaps a phone call from Microsoft, the Arrive has been replaced by the LG Lotus Elite. Hey, maybe they regularly rotate those phones and this is just coincidence, so we'll keep an eye on it, but at least for now the Arrive is spared the humiliation of being the iPhone 4S trade-in phone.
Source: Sprint; Thanks, Kien G., for the tip!