This week's Haftorah is the prophecy regarding the building of Beit Shlishi, Yechezkel's vision for the future. As part of the redemption of B'nai Yisrael the new Temple will be the Temple that lasts forever, a בית עולמים.
The Radak tells us that the coming redemption will also occur on Rosh Chodesh Nissan. The story of Pesach is above all the story of the founding of a nation. Leading up to Pesach we learn about a different aspect of the founding of the nation; the purification, the census, and our common history. Now we have the future, the building of the Temple just like the building of the משכן in the desert; a place for the on going revelation from Sinai.
Rav Hirsch points out that this is not a coincidence. We specifically read this section of Yechezkel to remind us of the future, to give us "the Divine instructions for the service at the Temple which is to be consecrated on that day". The message here is hope, there is a future. Pesach makes us a nation, it tells our history, now we're reading about our future.
Rosh Chodesh Nissan is not only the date of the redemption from Mitzrayim, but will also be the date when we return from exile. We may be moving back to Eretz Yisrael now, but until we have Beit Shlishi we are not redeemed.