There will be an LTE-enabled version of the ASUS Transformer TF300 (model name TF300TL) coming to Germany and Austria, launching mid August. It will go for €629 with keyboard dock and €529 without, which is around $650-$750 in US dollars. Hard to imagine the inclusion of a radio would boost the price that much, especially since you’re getting it through the carrier… the price is very steep for a more modest tablet (this is no Infinity).
The radio will work on 700 MHz and 1700 MHz LTE bands along with 850 MHz and 1900 MHz HSPA+ bands for fallback. If you live in Germany, expect to see it soon.