I wondered about that, too. That low price *may* only be good if you're using a plan at least as expensive as what you signed up with. Make sure you don't see any such restriction in the language and that you won't get stuck with a $35 or $36 activation charge if you can't get the change made.
Anyone have any luck getting a Droid for $49.99 and switching over to the data plan? Let us know!
As for the Nexus One, I've wondered how easily people can type on it, though I like how powerful the Nexus is. I didn't like the iPhone's virtual keyboard. I'm a touch typist and I don't like having to slow down so much as I did for the iPhone (which I took back).
I came across a thread on this exact topic a few days ago on one of those android/droid devoted forums. Someone posted a question about this amazon thing and was wondering what the catch was. The gist of it is that you *might* be entering in to two separate contracts; one with Amazon for 180 days for the hardware (droid) and one with Verizon for the 2 year contract.
The Amazon part requires you to be on a data plan for at least 6 months (you're "forced" to sign up at Amazon with one of their voice and data plans, however, you can change to the Unlimited Messaging w/ web, email, etc. plan.). If you are not on the plan for at least six months, then they will charge you for the non-contract price of the droid phone (minus the upfront $49.99 you paid for it).
The Verizon part is pretty simple: you break the two year contract, you owe the ETF (early termination fee), which I think is $350 (!!), but they might pro-rate somewhat for how long you've already been with them up to that point.
The important thing is to read the fine print, but Amazon is great to deal with compared to WireFly or some other 3rd party Verizon authorized vendors. That said, if I were you, I'd play it safe and just deal with Verizon all the way, meaning, I'd order the droid online (btw, use the code "webonly50" to get the droid for $149.99). I've heard great things about their customer service and how they do bend backwards to make you happy if you're reasonable. Yes, they are somewhat pricey compared to their competitors (Sprint, AT&T, T-Mobile), but you get what you pay for. Their 3G network is second to none in the continental United States, depending on where you live.
Regarding the Nexus One, well, I for one, was really looking forward to it coming to Verizon (T-Mobile has terrible 3G coverage in my area so their version of the N1 is out for me) later this month. Despite it's somewhat ugly and "manly" looks, Motorola really did a great job with this phone, hardware-wise. I just read about HTC (chinese manufacturer of Google's N1 phone) and how they used cheap plastic parts, especially on the touchscreen. I won't go into details, but so many users have been returning their N1 because the touchscreen has been acting crazy. The worst part of this is that since Google has been selling their N1 phones online (not available at a T-Mobile store or online at their website), the support for these phones are severely lacking. Some N1 owners who returned their phones due to malfunctions, have been without them for quite some time. Terrible suport. Google has great thing going but they are pretty stubborn about selling it on their own website themselves. Oh yeah, their 3G antenna is another thing.. seems like when you cup the phone on the bottom, you're effectively blocking the signal reception, dropping you down to EDGE speeds (T-Mobile) which is pitifully slow, It remains to be seen if Google ordred HTC to modify the hardware somewhat before they release them to Verizon. I'll keep an eye on this on one of the Nexus One forums.
There are other Android phones coming out that is worth keeping your eyes on... the HTC Supersonice and Incredible. Like I said, I'm just leery of HTC now, given all their problems with their phone hardware (Chinese mfg).
Whatever you do, read the fine print and ask questions! There are restocking fees ($35) and activation fees ($35, too) so if you are taking this lightly, then returning it, it will set you back, especially through a 3rd party vendor. That's why it isn't that expensive when you order it online at Verizonwireless.com.... they do waive the activation fee and ship it to you overnight for free, in addition to what other discounts you could get ($50). Also, see if your workplace or bank/credit union has an agreement with Verizon to offer employees/customers discounts. My wife works for the state of Tennesee, and we are getting our monthly bill discounted at 17 percent. Every little bit helps.
Let me know if you have any questions and I'll do my best at answering them. I've spent the last 3 weeks trying various phones and from various carriers as well as spent a lot of time on various forums learning new things every day.