Why might I want to know if the other party plans to call experts?
You will want to know about expert witnesses that the other party plans on calling to testify so that you have time to prepare for how to handle them at trial. Once you know who the expert witnesses are that the other side is going to call, you can research into their background to see if the expert is actually experienced enough to qualify as an expert. If the proposed expert has only been in the field for a very short time, or has experience in some other area that does not necessarily match up with why s/he is called to testify, then you can challenge the witness being recognized by the court as an expert.
Once an expert witness is called to testify at a trial, the party who is offering the expert will ask him/her questions to establish his/her expertise. The judge has to approve the expert witness to qualify as an expert in a certain area and it may be possible for you to object if the expert lacks enough experience.
Even if the judge agrees to qualify the person as an expert witness, thereby allowing him/her to testify at trial, your research might lead you to other things in the expert witness’s background that you could use to discredit the testimony of the expert witness. Expert witnesses can be a very effective piece of a person’s case, and if the other side can call into question the expert’s opinions and cause the judge or the jury to doubt the expert, it could have a major impact at trial.