Hey,
In my experience, there's a noticeable shift towards social work becoming a postgraduate career. The actual job market for social workers doesn't seem to really care all that much, as they just want solid education and graduates. However, universities have been put in a rather unfortunate position in regards to funding, and the options for postgraduate training are a lot more productive for a variety of social work departments. For example, I completed my training at Liverpool John Moores University, and the fees for the course were entirely covered by the NHS fees payment. However, those at BA not only had to deal with the more stringent financial restrictions attached to student finance, but they also had to pay £9000 a year for training, so they're now in a lot of debt. The breaking point for them was when the cap on NHS bursaries was introduced, as rather than divide their allocations between two courses, they got rid of the undergraduate course so they could devote all of their limited financial resources on the one course.
Others have done it differently, and I highly doubt there's going to be a point when undergraduate social work becomes non-existent. However, that forced push towards postgraduate resources is only going to result in that bar raising to a higher level, and it could be that undergrads end up sat in interview rooms surrounded by saturated applicants from the MA market. That's not necessarily a guarantee they won't get the job, but it becomes just another barrier to navigate that isn't anything to do with professional competence. Quite annoying really.
All in all, it won't be impossible to assimilate into the profession whichever route you take. However, my advice to anybody would be to aim for postgrad. The funding, if you can get it, is better, the fees shouldn't affect you (if you have a university who aren't greedy about it), and you'll be on the higher-end of the trained market.