I think I'll answer some questions for people who does not understand how the market works.
1) The reason this device will not support LTE is because of software. They pretty much run stock Android on nexus devices. If they wanted this phone to support LTE, they will have to form a contract with carriers that offer LTE. When that happens, the carriers can add whatever they want to the stock Android OS to meet their needs. You can also go read the presentation where he talks about how LTE just hasn't matured yet and they want to wait for that.
2) I'm not 100% sure why they wanted to leave out the SD card slot, but my only guess is that Google wants you to use their cloud service. They want their customers to upload their files on the Google cloud which will make the consumer buy other Google devices to share the ecosystem with.
3) If you noticed the Nexus devices, they always came out at the half-way point of Samsung/Apple's line. The Nexus 3 came out between S2 and S3 from Samsung, now the Nexus 4 is at the halfway point of S3 and S4 from Samsung. The reason is, Google has no way of competing against Samsung at the hardware point. If the Nexus 4 came out when S3 came out, there is no way they could have offered the Nexus 4 at the current price point. But, software wise, there is no way Samsung can compete with Google. To go from 4.0 to 4.1, first Samsung has to make adjustments, then they send that off to the carriers who make adjustments and the entire process takes 3-6months. While Google Nexus runs stock, which means there is no middleman adjusting with their OS and can send updates right away to the consumers.