I think the real problem that Apple and Google have to overcome for their watches to succeed is convincing people that they don't replace wristwatches, instead they are smartphone accessories. People have long given up wearing wristwatches and aren't looking to simply replace them with something else. The Apple and Google watches are really smartphone accessories, and the question to be answered is, do people want or need a smartphone accessory?
My belief is that watches need to be more than accessories for smartphones, and to achieve that they need to communicate with as many other devices and services as possible. The watches need to be accessories for desktop and laptop computers, appliances, cars, web browsers and more.
Note that right now Apple Watch needs an iPhone to work and Android Wear needs an Android phone to work. I don't think that watches need to be complete stand-alone devices, but I do think they need to communicate with more than just smartphones to be of the best use for enough people. Put another way, right now the potential market size for these watches is at most the same size as the respective smartphone markets. Do you want to be selling devices that have a market cap right from the beginning?
Dave Winer thinks that Apple Pay is the big deal in the announcements yesterday, and I think he is right. At the very least, the problem Apple Pay is trying to solve is much more significant and needed by all of us more than what Apple Watch or iPhone solves. What is needed to improve how we pay for things is open standards supported by all the significant players in the market at the same level as local area networking standards have been implemented in the past. We do not want payment processing standards to be like mobile broadband standards in the United States. At least Apple has adopted NFC for communication with Point Of Sale terminals.
It shouldn't take much for Google Wallet and all other wallets to implement the same one-time-use credit card numbers as Apple Pay will use. Hopefully that intellectual property is owned by the payment processors, who have incentive to see the same process used across wallets, than by Apple, who might prefer lock-in. Apple needs to advocate a standard architecture that all parties, including their competitors, can use, while adding value by making the process simpler and most secure on their devices.
The biggest risk for mobile payments is fragmentation caused by the mobile carriers. We can't have AT&T, Verizon, and T-Mobile implementing different payment methods and blocking the use of any other payment methods. The carriers have blocked the use of different wallets in the past, for example AT&T initially did not allow Google Wallet to work on their phones.
Here is an example of where payment processing can go off the rails for consumers if companies like Google buy companies like Mastercard. We need separation between the back end and front end infrastructures to insure there is a standard back end that benefits all of us.