I'll reiterate healthy11's comment, "Document everything in writing."

A very important aspect of having a child evaluated for learning difficulties is to document everything in writing...It is NOT adequate to just phone or talk, you MUST have a "paper trail." If, for example, you do have a casual meeting with the teacher, or with the principal in the hallway, follow it up with a written note, and keep a copy for your own records.
For example, "Dear (Mrs. Teacher), Thank you for taking a few moments to speak to me after school today, (date), regarding my son (name) and the struggles he's been having with (subject.) His dad and I are concerned, too, and we are wondering if he may have a learning disability. We expected an SST meeting to have taken place by now, and appreciate anything you can do to expedite the process..." (Check your state guidelines to see if there are time limits...) Also, sites like www.concordspedpac.org and www.wrightslaw.com have helpful information.

My husband and i have went through a STORM getting our daughters middle school to test her. All i can tell is continously , weekly sometimes daily talk with your son's teachers.

Talk with your child counselor at school and let them know you are interested in a psychological evaluation. Let them know that your child is not doing well in class assignments and having trouble with homework.And also call the school system social service department because they really help me get the ball moving.

Just my advice:
1. Force your medical provider to do a psychological evaluation.....first step to identifying ANYTHING. It will identify any type of attention problem your son may have. Why, bepcauce the school may claim this to be the issue and classify it as a medical problem.
2. Meet (many, many times) with the school and discuss your concerns. Ask for a plan of action. They may wish your child to see a counselor, or say that you need to go outside their system for evaluation. You will be able to provide your report that proves you are on top of the case and point out that you feel an evaluation is warranted. If you get no where with your son's school administration, go over their head...all the way to the local paper if you need to.
3. Handle this like any legal issue. Research, research, research......if you believe you know what your son has a problem with or can describe it, you will help those few educators who do care to be your best advocate.
-From a Mommy who got an IEP for AVLD for her ADHD 1st grader.

I went through this with my son and it does take awhile. They have a lot of data they collect and they have to report it back to you. Hopefully that is what is taking so long. The school learning disability specialist or the school theapist would be the ones to tell you whether he has "specific learning disability" this is what the schools now classify dyslixia and such under they don't give it a specific name. If you hear a lot of "we recommend you take your child to their peditrician then they think it's something bigger like ADHD but they legally can't tell you that. You really just have to stay on top of the school. You have to go directly the special education teacher or the princple to request any meetings or testing. Honestly, your childs classroom teacher should have requested testing from the sped staff if she was a good teacher.

Here are a few threads that may be of assistance:

community.greatschools.net/advice/213/How-to-request-the-district-to-evaluate--not-screen--your-child----

www.greatschools.net/search/search.page?search_type=0&q=request+for+evaluation&hiddenState=CA&c=topic