Just found when looking at the site the preorder date end is now set to 30 june and after that 2-4 weeks deliver of tshirt. So we can expect tshirt end of July.
If you participate in the pre-booking campaign and purchase the device when it becomes available, you will pay no more than 399 € (including VAT), excluding shipping costs and possible local taxes and other handling fees. The 100€ discount is valid through 30th of June 2014 - it is personal and non-transferable, nor can it be exchanged for money. No purchase necessary.