I got my iPhone 4 in September so my ETF is "down" to $260 😱. Even at the end of two years it would just be hitting $110 🙄. I'm in the opposite situation. I like tiered data which is why I came to At&t in the first place. But I had a run of bad luck a few weeks back and had 24+ dropped calls in two weeks. I never had so much trouble before then or since but it was enough to get me thinking about a Verizon iPhone 4. At this point, I would consider switching (or staying) for a family data plan. With 4 lines, I'm not prepared to cough up $30 per month per line just for data. At one point, as I was having all those dropped calls, I thought about taking my "mark the spot" text messages in to an At&t store to ask to get let out without an ETF because of poor coverage. Fortunately things got better before I got fed up enough to go in and do it.
In your situation I would avoid paying any ETF and just wait. Verizon was offering pretty significant rebates for people coming from At&t so you could see if they would cover your remaining ETF. I doubt it but it doesn't hurt to ask.