Did you think the debt crisis in Europe was over? Not so fast.

Major European markets tumbled between 1.4% and 2% today after two of Portugal's cabinet members resigned, sparking worries that a coalition that passed austerity measures may be cracking. Portugal's bonds jumped more than 1% to exceed 8% for the first time since November.  

To add to these concerns, oil is up 2% as an all-out upheaval in Egypt starts to look more and more likely. That could have a big impact on oil supply coming from the Middle East, although right now it's more speculation than reality. Wall Street still doesn't like what it sees, and in premarket trading the Dow Jones Industrial Average (^DJI -0.11%) has fallen 0.26% while the S&P 500 (^GSPC 0.02%) is down 0.31%.

Global markets will have a negative impact on Wall Street today, but the jobs market may cheer up some investors. ADP's jobs report for June showed an addition of 188,000 jobs for the month, well ahead of economists' expectations for 160,000 new jobs. This is a key signal that the Department of Labor's nonfarm payroll report may be better than expected on Friday. The Department of Labor released weekly jobless claims this morning, reporting that they fell by 5,000 to 343,000 last week.

After a short day of trading today, the jobs report will be out before markets open again on Friday, and it will drive stocks for a couple of days until earnings season kicks in.  

On a company level, investors should follow the never-ending saga of Dell's (DELL.DL) potential buyout. The company has already spurned Carl Icahn, and now Michael Dell himself is under pressure to increase his contribution if he wants to make a deal happen. Private-equity firm Silver Lake Partners has balked at adding to the pot in an effort to close the deal. One reason is that the PC market has deteriorated further since Dell brought up buyout plans -- and the company was unappealing enough as it was, even at that discounted price. Dell will certainly be the talk of Wall Street today.