From the website of the Western India regional council of the ICWAI, I retrieved the most recent placement statistics from page1 of the journal(http://www.icwai-wirc.org/pdf_files/June%202011.pdf).
Contrast this with the placements of the ICAI(retrieved from the campus placement report for Feb-11'Mar-11, reported on Pg 1724, of the May-2011 CA journal http://126.96.36.199/22701may2011journal.pdf). 35% of the candidates finally accepted the job offers.
The pan India ICWAI placement figures are not available, but I suspect that will portray a worse picture, considering that the best paymasters are typically in the Western Region(Maharashtra, Goa, Gujarat).
Why is this? Till recently(2007), as any informed person would attest to, getting the ICWAI certification was quite easy compared to CA, and the curriculum was dated. While one may say that given the (often) considerable work experience profile of the candidates, they would anyway be knowing the relevant costing practices etc, this did not reflect well on the course. Add to that the notoriously inefficient administration, Kolkata HQ(and concurrent attitude!) and the trend of blindly aping the exam papers of other institutes, and you see why this had happened. Employers did not much rely on the ICWAI qualification, and those who got it were typically those with considerable experience, who considered it an added feather on the cap.
Since 2008, things have changed. Administration has improved and become more student friendly/responsive, there is a world class curriculum in place, and there is the requirement to do a mandatory 3 years internship(or workexp in lieu of that). That should address the supply side-both quality and quantity wise. The Indian Government obliged the profession by making cost audit mandatory. While opening the floodgates to cost auditors, the real juice may seem in the added services like efficiency assessment etc. But there, they do face a competition from CAs and management consultants.
My conclusion: Cost Accountancy firms will mushroom, but the corporate demand for Cost Accountants is unlikely to go up. While firms will pick up candidates, they would not match the industry pay. So this state of affairs is likely to continue atleast till companies realize that they need cost accountants, in addition to their existing accounting/finance professionals.