The news coverage of this is kinda interesting, if you'll forgive me using the term, in that seeing a Tsunami play out in real time on live TV is on the list of things you'd likely never think you'd see happen*.
That said, the first thing that pops into my head watching these waves wash mud and debris through northern farmland is that there's going to be a local need for food, short and long term. Current crops are gone, while future crops are going to require substantial remediation of fields due to the realty that they are now buried in an assortment of whatever gunk the wave has picked up in its travels inland (I'm currently watching a wave eat houses and buildings while, at the forefront, a small fishing boat is being carried along the crest). Rice futures are probably going to go nuts on the commodity exchange today. If our government or aid agencies are going to respond, this is likely the best area to target because, financially, Japan is capable of absorbing the damage.
No one has any idea what the casualties are going to be like yet but, judging from the state of this town up north - houses, facilities, hell... there's an airport flooded under up to about half way up the first floor and I'm really hoping there were no planes on the ground because the terminal docking portals are otherwise eerily vacant... it's not going to be a good day. Aftershocks are still hitting now about 2 hours after the event; hopefully that's all that happens and there's no followup Quake in the immediate future.
The Tsunami from the initial quake is now making its way across the Pacific with multiple landfalls expected in the next few hours. Hopefully with this lead time the local agencies are getting out the alert so that no more lives are lost elsewhere.
* I was surprised at how long it took CBC and CTV to get on this. I was flipping back to them to try and get another perspective fron them for almost an hour while BBC World and CNN have been covering before those former two got going on it at 3:00AM EST. It didn't even make the Ticker: which is striking in demonstrating just how unprepared the two news organizations were to handle something catastrophic happening outside their standard operating hours.