It's very likely that it will still just be a "Send" button. Channel management and all that will actually be handled by the software automatically. You put money into your LN wallet, and it will use that to open and close channels automatically. So when you want to send Bitcoin to someone, your LN wallet will have established several channels. It will also determine an optimal route and do everything automatically for you. There's no need for you to manually open and close channels yourself; the software will handle all of that for you.
That sounds nice in theory. The problem I see with this approach is that people would expect to pay "zero fees" or at least "low fees" when using a LN wallet, but if the channel management is totally automatic, then now and then they will be charged high transaction fees (e.g. if they pay something on a regular workday with high network load and the client just needs to open a new channel) and will be surprised that they have, from one moment to another, $10 less (or even more, we don't know how fees will evolve, but I don't expect them to be much lower than now if there is more adoption).
If people instead knew that they should open payment channels when there is low network congestion and fees are low, then I think acceptance will be higher. I for myself would use a client which lets me choose the point in time where I do the "expensive" channel-opening transaction, and above all, I can select how many channels, and to whom, I want to have open (no algorithm can detect potential scammers, and the algorithm can also not know if the first TX I do is to someone with whom I will make payments frequently).
Because of these usability issues, I expect that Lightning will see broader adoption if exchanges adopt it, because they are normally the places where you get your Bitcoins from. And exchanges unfortunately are the most used Bitcoin service now. Exchanges will open channels with you for no fee or only a low fee (less than the transaction fee), and the most lazy of us will continue to use their online wallets so they don't have to care about channels (so you won't even know if they're using LN or some centralized clearing system ...).
That is not necessarily negative, but it means that the network will be, at first, pretty centralized, and then it could slowly evolve into the decentralized network that most "anarchist" LN supporters want it to become.