Your MacBook is going to run hot just because it is a system that runs hot. All notebooks these days do whether they are from Apple, Dell or anyone else. 180 deg. Fahrenheit is to be expected
Desktops however can run cooler since they have room for better cooling systems. However, if it is reaching 155F (which is 68 Celsius) under load I wouldn't be worried about it. While it could be better it isn't going to be the end of your system. Not by a long shot. My PowerMac for example regularly runs at 66-69C at idle. A typical, well-cooled system typically runs between 60-65C idle.
Most OEM computers go a bit weak on the cooling system in order to cut back on noise and costs. If you want your system to run cooler, then look into after-market CPU coolers. You can net some very good units from Zalman, CoolerMaster, Thermaltake etc. for about $40. The coper-finned-heatpiped Zalman's are very good.