It is an on going question on the forum. My first question is, was a deposit given? and does the cuemaker have a good rep? If both are yes then just try to be patient. If the first is yes and the second is I don't know or no then, you may want to press alittle. It really depends on who the maker is. Run their name thru the search function and see any history, if any here. As Craig mentioned above, A lot of variables come into play, and depending on those, should dictate your response. It also depends on a time frame that was given. If they said 2 months for a custom built cue, I'd figure 2 things, full of BS, and 2nd, Not happening. If they said 8-10 months, and their rep is good, then I'd cut some of slack.
I just cored about 25 pieces of burls and soft woods this weekend. Some of which I have promised into some cues for friends, including a donation to a teamates Jack-n-Jill party in July. I stabilized quite a bit of those pieces prior to this, using very expensive stabilizer. While putting the newly cored pieces into a box to take from the shop into the basement, I dropped a couple. A nice spalted piece hit the floor and split apart!!! It was going into an ebony cue, for the Jack-n-Jill raffle, but.....not anymore

Things do happen, but some makers, it happens more than not, so it's important to know who your dealing with. It's hard to give an appropriate response to your question, as more info is needed, such as time frame given, how much time has really passed, etc. If no deposit was given then you can move on, But, just as a curtousy, let the maker know, for 2 reasons, he may rethink his time estimations for the future, and 2, he may do things differently for future orders due to losing business. Just my thoughts.
Dave