Naturally they can't wave a magic wand over anything to solve your problem, but if you are paying for a good pedi (ie one that includes the works like massage etc, not just a file and polish job), they can definitely go a fair way towards helping smooth things out, as well as providing you with tips and products to use at home to keep things nice and try to improve cracked heels over time.:
One little trick you can do without the need to see a manicurist is to invest in some good-quality body butter (obviously you can choose from a huge range at any old department store or try Body Shop etc for some really yummy ones), and slather it onto your feet every night before bed, then pop on a pair of thick cotton socks and let it soak in overnight. You will notice a difference the next morning but keep going with it and see just how amazingly soft and nice your feet will get with regular treatment like that. You can slough away dead skin with a pumice in the shower/bath at night and then apply the body butter and watch the cracks disappear!
