Since I can't get a new phone on contract again (don't want to lose unlimited data on Verizon), I'll probably buy a used Galaxy S3 some time next summer - by then it'll hopefully be $100-200 for one that's in good shape. The Galaxy S3 has a strong modding community around it, so I can just install a stock Android ROM and things will be fine.
> I would think that a replaceable battery also extends the life of the device in general for people who don't necessarily need the latest and greatest every year or two, since it's easy to just buy a new one and pop it in when the old one starts to lose its ability to hold a charge.
Don't forget about the option of getting a bigger battery when it can be removed, for those who need their phone to last longer.