Stablize f2.8 workhorse zoom time with a review of the new Tamron 24-70mm f2.8 Di VC at DC Watch Impress which you can also read as computer translated.
The PentaxForums blog has posted a comparison review between the Sigma 10-20mm f3.5 DC and the 10-20mm f4-5.6 DC. As you can expect from the website name, they tested the Pentax K-mount versions :)
This lens has not even been formally announced yet, but it comes out with a review! It is the highly anticipated Panasonic 12-35mm f2.8 (M43rds) reviewed at DSLR Magazine (computer-translated).