There's a lot going on in the markets today. 

The Philadelphia Fed Survey plummeted to its lowest level in 6 years down -20.9 whereas estimates were -1.3.

Housing starts were expected at 1.14m and only came in at 1.006m, the lowest level of permits in 12 years!

Merrill lynch obliterated analysts expectations with a write down of 16.7 billion.

All of the above have led to weakness in stocks and some slight strength in MBS's.  We're currently up about 5/32nds on the 5.0% coupon.  So expect slightly improved rates this morning.

The jobless claims report actually came in slightly better than expected, but the variation hasn't even made headline news.

To top it all off, Bernanke is currently getting grilled by congress regarding a short term economic stimulus package.  The traders read of that testimony has the potential to greatly impact markets.  So there is potential for great volatility after that testimony.  The current interchange between the congressional committee and Bernanke amounts basically to congress trying to force Ben to tell them exactly to what extent the economy will slow and for how long. 

Be ready for quick change in the markets, if Ben drops a bomb.  If you don't have the resources to access news outlets with traders opinions of the testimony, it would be safer to lock.  I would keep an eye on bloomberg/cnbc to gauge the markets opinion.  If the markets like the news and stocks start to rally, locking is probably your least risky bet.