A rather exciting paper appeared on ePrint a few days ago: http://eprint.iacr.org/2010/006.pdf
A team of researchers succeeded in factoring a 768-bit RSA modulus.
In many practical applications nowadays, we use a larger 1024-bit RSA modulus for signatures and encryption. This result raises a question of "For how long are 1024-bit encryption/signatures secure?". The authors claim that they are for the next three-four years, and suggest switching onto larger modulus such as 2048.