Today Software Testing is not a low end task. Testers are doing variety of testing. Sometimes developers are moved to Test Automation and Performance Testing. I am sure that Code development skills improves Tester's ability. Many test expertises have said about it. I found one interesting article at Testy's blog. He has analyzed in depth. Link ==> Do testers need programming skills?
The below quote content is from I.M.Testy's blog
The debate over whether testers need to at least understand programming concepts is still raging within the discipline. To me this debate is puzzling because it seems to suggest that as a professional, I don't have to really understand or be completely proficient in critical aspects of my trade. Even Cem Kaner noted, "I think that the next generation of testers will have to have programming skills." Actually, there was a time not so long ago when testers had to have programming skills, so it is nice that Cem now acknowledges that skill as useful in testing.
Unfortunately, occasionally even within Microsoft a few people still want to differentiate between STE and SDET by blindly assuming that STE meant non-programming testers. The fact is, that the old STE ladder level guidelines clearly stated skills such as debugging production code, and design and develop effective automation as required skills for Microsoft testers. Unfortunately, some managers chose to selectively ignore these skill requirements and some groups chose to differentiate between GUI testers and any tester who could write code by labeling them as STE and SDET respectively. (This was a horrible abomination of job titles in my opinion.) The new SDET competencies at Microsoft are designed, and supposed to be implemented in a manner, to reinforce the essential skills we expect from our testers so a tester at a certain level in their career stage in one business unit essentially has equitable skills of any other tester at the same level in their career stage in any group in the company.
